Citibank has denied that its systems for phone banking were down for two days due to an IT upgrade but admitted customers did experience delays.
A Citibank cardholder told Computerworld that Citibank's systems for phone banking were down over the weekend of November 30 and December 1.
The customer said that the customer helpdesk was not taking any calls over that weekend.
Paul Newham, director of operations at Citibank said that the bank's customer service centre -- a 24x7 operation -- was operational but "was experiencing high call volumes".
"Some customers may have had some difficulty in getting through, but all of our IT systems were functioning over this period," Newham said.
He said Citibank recently implemented a range of IT initiatives to enable the bank to "deliver the best operating platform for credit cards in Australia and servicing tools for all Citibank customers".
Without giving specific technical details, Newham said the technology upgrade went according to plan and included "reissuing a major portion of our credit cards to Citibank customers".
"For the security of our customer's accounts, this was conducted in a controlled manner over a four- to five-week period. The number of customers wishing to activate their new credit cards through our customer service centre has meant that we have been experiencing high call volume during this time," Newham said.
Newham said Citibank has increased the number of customer service staff to handle the increase in enquiries.