Some First Credit Union customers have been hit with issues after the bank migrated to a new core provider and a new debit card provider.
One customer got in touch with the Herald saying she was unable to use her Eftpos card or internet banking.
Another complained to the bank's Facebook page that they were stuck two hours from home without money after their card stopped working.
"I can't get home to pick up my kids from school because the old card isn't working and neither is the new one," they wrote, "I'm furious I'm having to take my satnav into a pawnshop to get the money to get home!"
Other customers have complained about long delays on the bank helpline.