(CNN) – Erik Roberts, an Army sergeant who was wounded in Iraq, underwent his 13th surgery recently to save his right leg from amputation. Imagine his shock when he got a bill for $3,000 for his treatment. “I just thought it was bull—- that I’m getting billed for being wounded in Iraq doing my job. I always put the mission first, and now that I was wounded in Iraq, they’re sending me bills,” he said.

“I put my life on the line and I was wounded in combat, and I came back and they’re not going to take care of my medical bills?” It’s a level of outrage shared by his mother, as well as the doctor who performed the surgery. “It’s hard to understand why we’re not taking care of guys like Erik whose injuries are clearly related to their service. They deserve the best care of anybody,” said Dr. William Obremskey, an Air Force veteran and surgeon at Vanderbilt Orthopaedics in Nashville, Tennessee.

“For him to be responsible for $3,000, I think, is a little ridiculous or is uncalled for, particularly in this situation.”

His mother, Robin Roberts, put it more succinctly: “Why should any soldier pay one penny of a medical bill from injuries that occurred while they were fighting in a war? That’s what really frustrates me.” The Department of Veterans Affairs has now decided to pay his bill, but only after prodding from a U.S. senator who got involved after CNN brought it to his attention. He retired from the Army in October 2007, because of his war injuries, and enrolled in college last fall at Youngstown State University, majoring in finance and minoring in economics.

But in December, he says, a golf ball-sized lump appeared on his wounded leg. He says he went to a Veterans Affairs hospital and was told not to worry about it.

A few days later, he says, he went to the emergency room after the lump flared up more. A doctor there, he says, told him that the leg was badly infected and that it might have to be amputated. His leg was saved. The $3,000 billed to Roberts wasn’t for the surgery itself. It’s a portion of the bill for six weeks of daily antibiotics to prevent the infection from coming back. His private insurance plan picked up the majority of the $90,000 in costs.

Roberts has been administering the drugs himself — up to seven IVs a day, with a nurse coming to his home once a week to check on him. At one point, his mom says, the insurance company suggested the war veteran should be put in a nursing home to receive the round-the-clock antibiotics.

“Now why would you want to put an injured soldier who is 25 years old in a nursing home to get IVs?” Robin Roberts said. “He said, ‘Send me home and teach me to do it myself.’ “