In the past five days Westpac's Internet banking site has suffered a litany of computer glitches and outages that culminated in a few thousand customers losing funds from their accounts over the weekend.
While unwilling to disclose dollar figures, a Westpac spokeswoman confirmed debit transactions were mistakenly duplicated for a "few thousand" Internet customers on Friday.
"This is only a handful of our 1.5 million Internet customers," she said blaming the problem on human error during a system change, with the bank renaming a database.
She said customers financially stretched by the mistake were assisted with temporary overdrafts or extensions on their credit cards.
Earlier in the week, angry customers had contacted Computerworld because of a site outage that began early Wednesday morning.
The spokeswoman said the bank had to reboot its mainframe after a "small hardware glitch".
However, by Thursday afternoon customers continued to contact Computerworld claiming they were unable to undertake Internet banking transactions, because the RSA tokens were inoperable.
Confirming the disruption to Internet banking customers, the spokeswoman said it was a "middleware glitch".
As of this morning she said there were no outages, glitches or disruptions so just maybe it is the start of a better week for Westpac's Internet banking customers.