Target Corp. said it was adding staffers to phone banks set up to handle consumer questions about the data breach involving customers' credit cards and would keep them operating 24 hours a day, even on Christmas.

"We continue to listen, especially to tweets about call center wait times," Target said in a series of Twitter messages Tuesday. "We will not be satisfied until all guest needs are met."

The Minneapolis-based retailer has been inundated with calls from customers after confirming last week that its point-of-sale system, which consumers use to swipe their credit and debit cards, had been hacked with software that absorbed account numbers and sent the information to attackers who haven't been publicly identified.

The breach raised the prospect that customers' credit or debit cards could be used by thieves, though such theft appears limited to date. Banks and credit card providers have been monitoring the increased potential for fraudulent use of cards that were used at Target. A handful of banks, most notably JPMorgan Chase & Co., have since limited the amount of money their customers could withdraw or purchase on debit cards that had been used at Target.

The retailer has taken to social media several times in the past few days to reiterate statements it has made to the media and on its website about the data breach. As well, it has used Twitter, Facebook and other online tools to point customers to a page on its website with answers to key questions about the situation.

On Monday, the Justice Department joined the investigation of the data attack and search for persons responsible for it. Meanwhile, Target's general counsel held a conference call with state attorneys general, who often bring legal actions on behalf of consumers, to inform them specifically of what private information was accessed and the progress of the company's investigation into the breach.

Evan Ramstad • 612-673-4241