DENVER (AP) -- A computer hardware problem caused more than 800,000 credit and debit card transactions to be double- or triple-billed last week at stores nationwide, including Wal-Mart, officials said.
Staci Busby, a spokeswoman for First Data Corp., an electronic payments processor, said Sunday the excess charges on MasterCard and Visa accounts had been reversed. She said she did not know details of the hardware problem.
Busby was unable to say how many customers were affected by the 800,000 transaction errors, but said they involved retailers including Wal-Mart.
"Anyone who conducted a transaction with a Visa or Mastercard on March 31 should check their statements," she said.
The errors were posted to customers' accounts on April 1. "First Data corrected the problem as soon as we discovered it," Busby said.
Busby said besides publicizing a toll-free hot line, Greenwood Village-based First Data was calling affected customers. She said some people may not see the reversed charges on their accounts until Tuesday.
Wal-Mart spokeswoman Danetta Thompson said cashiers were told about the mix-up and store signs were posted with First Data's toll-free number -- 888-893-0626.
(Copyright 2004 by The Associated Press. All Rights Reserved.)