Banks in Australia and New Zealand have been working round the clock since the weekend in an attempt to reverse around A$45 million (around 18 million squids) worth of duplicate transactions.
Apparently, corrupt files sent from ANZ bank to other banks which issue Mastercards caused around 400,000 transactions to be double-counted on customers' accounts in the Southern Hemisphere.
The BusinessDaily newswire reckons that around 200,000 credit card users in Australia and overseas had been hit with the double charging.
ANZ Bank, meanwhile, has confirmed the cockup, although details of how many punters have been affected have not been revealed.
I wonder if MasterCard will put this factoid in its upcoming IPO prospectus?...