LOS ANGELES — Bank of America Corp. told 2,500 mortgage origination staffers this week that they would be reassigned to loan modification duty, two weeks after the bank promised Congress to provide better service to distressed borrowers who sought help in avoiding foreclosure.

The effort attempts to address a persistent complaint of borrowers caught in the 3-year-old foreclosure crisis: being bounced from bank employee to employee as they tried to work out a way to stay in their homes, often being told different things about their case in each conversation along the way.

Bank of America, the giant Charlotte, N.C., lender, became the largest servicer of home loans in 2008, when it acquired Calabasas, Calif.-based Countrywide Financial Corp., the aggressive No. 1 mortgage lender. Bank of America came under fire last month at a Senate Banking Committee hearing into mortgage servicing, which is the business of billing, collecting payments and handling delinquencies and foreclosures on home loans.

The bank’s mortgage chief, Barbara Desoer, said at the hearing that she was instituting a new “case officer” system so customers need no longer explain their situation to a different employee on every call.

“We know this goes to the heart of many customer complaints that you have heard,” Desoer said.