Barclays has apologised for charging customers double when they used their bank cards.
The bank said the duplication payments across an undisclosed number of accounts had been caused by a 'small technical glitch'.
It said the problem had now been fixed and insisted no customer had been left out of pocket.
Barclays customers said they were 'frustrated and worried' by the duplication of deducted payments
However frustrated customers said they were 'worried' the duplication of deducted payments had happened again.
A similar problem hit the bank in October 2015 and 2016.
Linda Taylor, 31, a social worker from Milton Keynes, told MailOnline: 'Barclays Bank have once again had a glitch with their system and duplicated payments. They are cagey as to why this has happened. I had over £300 in duplicated payments - totalling £600.
'The phone lines had over an hour waiting times and when I called earlier they said it would be fixed the same day, but wasn't. This happened to all customers who spent on their card on December 31. Customers were refunded this afternoon.
'It's very frustrating and worrying this has happened