PHILADELPHIA (CBS) — How often do you check your credit report? Statistics show that anywhere between 25 and 80 percent of credit reports have mistakes that might be hurting you. That’s why it’s critical that you know what information is contained in your report.

Rodney Carvalho is positive he’s never had an appendectomy. So he was surprised when his mortgage broker ran a credit check and found a collection agency was claiming that he owed $2,800 to a doctor in Texas for an operation he never had. When he called the collection agency to ask them to remove the notice, Carvalho says, “They were unwilling to do it.”

Carvahlo was trying to buy a house, and the erroneous notice caused his credit score to plummet from a near-perfect 813 to a not bad 708.

Jim Donovan reports…

Since cases like this could involve identity theft, experts say victims should immediately file a police report. Then, they recommend contacting all three major credit reporting agencies–Equifax, Experian and TransUnion–to ask them to remove the false information.

Jay Foley, of the ID Theft Resource Center, says it should take about three months to set things straight.

“If you do everything right, the negative debt comes off your credit report, and your credit score goes back up to what it should be. It’s like it never happened,” Foley says.

As a result of the bogus debt, Carvalho is now taking extra precautions, like checking his credit report regularly for suspicious activity.

Federal law allows you to obtain one free credit report a year from each of the three credit reporting bureaus. Click here to obtain your FREE credit report.

Reported by Jim Donovan, CBS3