Payments processing problems associated with the change over to a new Cuscal switch created further inconvenience for credit union and mutual bank customers over the weekend.Most of the difficulties occurred on Saturday morning, with the problems largely being resolved early in the afternoon.Numerous credit unions published apologies on their websites about the issue.Credit Union SA listed ATM transactions timing out, and Eftpos and Visa transactions being declined among the issues customers faced.Customer difficulties highlighted on social media included funds being debited from accounts, even though transactions were declined.Credit Union Australia, Sydney Credit Union and Police Bank advised customers to check their balances before making purchases.People's Choice Credit Union opened some branches on Saturday to help customers, while some credit unions extended the operating hours of their contact centres on Sunday.Adrian Lovney, general manager at Cuscal, said in an email yesterday that the processing issues were the result of an "isolated database software problem, affecting cardholders intermittently between 10:40am and 1:20pm, at which point it was contained and resolved."He said that where a transaction may have been authorised but not completed, Cuscal immediately processed reversals, "and the majority of those have now occurred."Lovney said the switch was "stable and handling transactions at a far higher rate than we had anticipated at this point."He said the switch saw transactional volumes, including reversals, exceed 100 transactions per second yesterday afternoon.Late last week, Commonwealth Bank confirmed that it was partly responsible for some duplicated transactions earlier in the week, for some credit union customers, after double-handling a file.Separately, yesterday, ANZ blamed a software upgrade on Saturday night for interruptions to internet banking and phone banking services on Sunday morning. The bank said it restored services around 2pm.