Customers are threatening to quit the Co-operative Bank after its mobile app stopped working for three Fridays in a row – it was down for the whole of last weekend – and then went down again within hours of the bank declaring it was fixed.

The latest incident, which left thousands of customers effectively locked out of their accounts for about 48 hours, has, it seems, proved the final straw for some.

Customers – some of more than 20 years’ standing – have been queueing up on the bank’s Facebook page and othersocial media sites to declare they have run out of patience and will be switching to another bank.

“My switch went in to another bank this morning. It’s a shame, but with no access to mobile, internet and phone banking (I tried everything) for days, plus no customer service available at weekends, it was time to go,” wrote one frustrated customer.

“App down again this weekend so couldn’t move money. Had to call, was on hold for 35 minutes before cut off as offices shut. I’m moving accounts – I’ve complained to them too many times and they don’t learn or understand customer needs,” wrote another.

The most recent problems with the app started on Friday 17 March. It then went down the following Friday. It was out of action again on Friday 31 March. It was reinstated at 11pm on Sunday, only to be taken down again for maintenance less than 24 hours later.

This is the latest problem to hit the bank. In August 2021, Guardian Money reported on claims that it had become almost impossible to get through to anyone at the bank’s call centres because of a shortage of call-handling staff. The problem persisted into 2022, when there were also problems with the app.

In recent years people have become increasingly reliant on mobile apps to