Staff at the bookmaker Betfred have complained that they were left unable to pay bills – and in one case having to use a food bank – after a system that allows employees to access their pay in advance failed.

Posts on an internal chat system, seen by the Guardian, indicate that some of Betfred’s 8,000 employees faced financial hardship over the course of at least two weeks, as the company struggled to fix a problem with Wagestream, an app that staff can use to access up to 40% of their monthly payslip in advance.

Betfred, owned by members of the billionaire Done family, headed by Mancunian brothers Fred and Peter – who gave £375,000 to the Conservatives in 2016 and 2017 – said on Tuesday that it had “resolved” the problem.

Wagestream is one of a relatively new breed of “salary advance schemes” intended to give staff more control over when they receive their pay and help them avoid costly credit alternatives, such as payday loans.

In the chat messages, one staff member said she knew “people who have switched their bills to weekly and are now missing those payments”, while others raised concerns about their ability to afford to travel to work.

Another said they had “managed to now get myself into debt and not afraid to admit Iv [sic] now had to use food banks and rely on people’s generosity to get me through the past two weeks”.

The employee asked: “Where is the help from Betfred when this arises? They have allowed this mess to happen.”

Betfred did not answer questions about what measures it had put in place to support affected staff while access to the Wagestream salary advance facility was being restored.

A spokesperson said: “Working with our suppliers we have identified and resolved the issue. We will be speaking to our staff directly.”

The problem is understood to have begun when Betfred switched between two pieces of software used to manage shifts and payroll data, migrating to a platform called Shopworks.

A spokesperson for Shopworks said: “There was a problem two weeks ago relating to the transfer of data to Shopworks from one of the other technology providers that Betfred use, that caused some issues for Betfred’s payroll team.

“Faulty data meant that shift and pay information could not be uploaded to Wagestream[’s salary advance facility], rendering staff unable to access it.”

Under the salary advance scheme, Betfred staff can dip into up to 40% of their monthly pay, in exchange for a transaction fee of £1.75.

Another staff member wrote on the internal chat system that they were pleased that they could not access Wagestream’s salary advance facility, because they had come to rely too heavily on it.

Wagestream also offers other services including budgeting support and savings accounts which were unaffected by the outage.

The Guardian has approached Wagestream for comment.