The recent TV advert celebrating British Airways’ 100th anniversary was framed as a love letter to Britain, narrated by national treasures such as artist Grayson Perry, astronaut Helen Sharman and a phalanx of sporting stars.

“We love you, Britain,” gushes Oscar-winner Olivia Colman.

The problem for BA is that neither Britain, nor the rest of the world, appears to love it back. The past few years have been punctuated by a series of lingering headaches – a mixture of bungling and sheer bad luck.

The fragility of BA’s IT security was laid bare last year when hackers stole the personal data of half a million customers, a breach that led to a £183m fine from the Information Commissioner’s Office.

Last month a computer systems glitch meant that more than 500 flights were cancelled or delayed, causing chaos and misery for tens of thousands of passengers.

In the past week BA has further incurred the anger of its customers with its cack-handed response to a series of pilots’ strikes due to take place in September. Customers complained of being told, incorrectly, that their flights had been cancelled.

Some rebooked with other airlines, only to find their original bookings were back on after all. Others could not reach the airline by phone, despite trying dozens of times.

David Burnside, head of public affairs at BA for nearly a decade from 1984, remembers when the airline was still seen as the global pinnacle of aviation. “BA is still a good international airline but they keep running into mistakes and they seem to have lost their aspirational drive,” he told the Observer.

“They dropped [the advertising slogan] ‘the world’s favourite airline’ around the beginning of this century. That was an aspiration that kept customer service at the forefront of people’s minds. If you claimed it, you had to maintain the standards.”

While there is an element of misfortune about BA’s recent travails, those standards do appear to have been slipping. Complaints include the removal of free food on short-haul services, cramped business-class cabins and dog-eared interiors.

Amid a chorus of passenger disaffection, the one-time “world’s favourite” sank to 31st in the 2018 airline rankings produced by Skytrax. The lacklustre showing saw BA fall below relative newcomers such as Malaysia’s Air Asia, as well as the likes of Russia’s Aeroflot, a byword for dilapidation just a decade or so ago. BA recovered somewhat in this year’s rankings, but still only claimed 19th spot.

A recent survey by consumers’ organisation Which? rated BA 83rd out of 100 UK companies for quality of service. In another Which? survey, consumers offered some insight into that lowly status, deriding the airline’s premium offering for cramped seating, “inedible” food and poor entertainment options.

One passenger said that BA’s premium cabins were little more than “Ryanair with free food”.

John Strickland, director of independent transport consultancy JLS Consulting, worked for BA after privatisation and recalls how the former national flag carrier successfully shook off the running joke that its initials stood for “Bloody Awful”, improving rapidly under the stewardship of the late Lords King and Marshall. “At that time BA was so far ahead, but we didn’t have low-cost airlines on short-haul or serious long-haul competition in a meaningful way side by side at Heathrow. The Gulf carriers were embryonic,” he said.

“Having established that lead in the 80s and 90s, BA fell behind in recent years, taking their eye off the ball, particularly in premium. They’re very aware of that and they’re actively trying to put it right but it’s not like changing the wrapper on a Mars Bar, it’s a medium-term investment, taking at least a couple of years, to fully take delivery of new aircraft, refit cabin interiors and retire some older aircraft.”

Strickland acknowledged that some of the airlines that won plaudits for their superior long-haul service, particularly in the Middle East and Asia, enjoyed advantages that BA did not, such as state subsidies or low labour costs.

Burnside felt that BA has become trapped between long-haul rivals with their luxurious offering and low-cost carriers that had emerged over the past two decades. “On the route that I take almost weekly, to Belfast, it’s a premium price that’s being charged and frankly the service is no better than easyJet,” he said.

“To not give people a cup of coffee and a packet of peanuts is a bad mistake. It irritates people when they’re paying hundreds of pounds for their ticket.”

On long haul, Burnside said that regardless of what advantages some rivals offered, BA could not afford to be left behind on quality. “They’re losing business to Middle Eastern carriers. I know people deciding to fly Turkish to Istanbul rather than BA because it’s a better service, or to Bahrain on Gulf Air.

“The cost [of improving service] might be a bit higher but otherwise you’re losing business class travel.”

BA’s chief executive, Alex Cruz, countered: “We are proud to fly more than 45 million customers a year and, while challenges remain and change takes time to deliver in aviation, our customers are noticing the investments we are making.”

The airline is taking delivery of 73 new aircraft including A350s and 787s, refurbishing its long-haul cabins, and redesigning its airport lounges. It is also promising revamped in-flight menus and upgraded bedding for premium passengers. There will also be a new Club Suite for business class.

BA can afford this much-needed investment because all that cost-cutting has made for bumper profits. Accounts for parent company IAG, formed via the £5bn merger of BA and Iberia in 2011, show that the British part of the airline is by far the most lucrative, reporting operating profit of €873m (£790m) in the first half of 2019, having made nearly €2bn for the full year in 2018.

But while profits have held up, shareholder sentiment has tracked BA’s very public travails. Parent company IAG’s shares are down by a third over the past 18 months.

And while staff at the coalface are working hard to rebuild BA’s image, their effort has been overshadowed by senior management becoming embroiled in potentially distracting rows. Earlier this year the airline appeared to be having a spat with the Financial Times, when it stopped providing the paper on flights, in its lounges or at gates worldwide. BA insisted the decision was simply the result of a review, but the FT described the decision as abrupt and insiders at the newspaper suggested BA’s action was linked to what the airline viewed as unfavourable coverage.

More recently, IAG chief executive Willie Walsh made strong criticism of Heathrow, accusing the airport’s management of dishonesty. BA also lost friends in the gay community when it did not follow Virgin Atlantic’s example in refusing to deport LGBT asylum seekers, a decision that spawned allegations of hypocrisy given the airline’s sponsorship of Brighton Pride.

With strikes looming, and amid operational failures, high-profile rows and customer dissatisfaction, BA will have to hope that its multibillion-dollar investment in quality of service will soon start to pay off.

According to branding guru Mark Borkowski, glossy celebrity-fronted advertising campaigns won’t do the trick on their own. “If a brand is going to change, it has to change from the top, from people really wanting to do it, and most of the posturing BA has done about who and what it is just isn’t authentic.

“The advert initiatives don’t match the brand and what it delivers. They just make us realise what BA once was and no longer is. You can’t advertise yourself out of a bad reputation.”