EDINA, Minn. — As a longtime debt collector, Lesllie Rogers has been routinely insulted, pummeled with obscenities, crudely propositioned and threatened with violence by the people she calls.

“They want you to feel as small and insignificant as possible,” said Ms. Rogers, who works for a collection agency in Rochester, Minn. “The guy who sits across from me just was threatened with getting his legs and arms cut off.”

Debt collectors like Ms. Rogers are well aware that they are not a sympathetic lot. But now they are saying enough is enough. The trade association that represents them is engaged in an unlikely charm offensive to change their lowly image, while also trying to shape the rules that govern them as they face the prospect of a tough new regulator.

Debt collectors as human beings? It could be their toughest commission yet.

These are boom times for collection agencies, which have been swamped with work as many Americans gorged on debt and then struggled to repay it. But the industry has come under fire for pushing too hard. Last year, 140,036 complaints were filed against debt collectors, a 17 percent increase over the previous year, according to the Federal Trade Commission.