1) you need all three separate credit reports not the 3 n 1. find out which bureau reported the negative tradeline.
2) dispute with credit bureaus that reported the negative tradeline. Experian, Equifax, &/or Transunion
3) do not dispute online because it gives the credit bureaus 45 days to respond vs. 30 days. do it by certified mail return receipt
4) Never call a credit agent over the phone they tell lies & violate. get their violations in writing
5) don't pay a dime until they validate. a paid collection is still a COLLECTION
6) check your state statue of limitations on debts to see if the debt is time barred.
7) After the steps BELOW fail (if they fail) if the debt is not time barred and they can validate negotiate a pay for delete in writing.
8) if the credit agency verifies with the credit bureaus immediately send them a debt validation ltr (google it), by certified mail return receipt
9) in that letter they must show proof the debt is yours with signed docs, something with your signature on it, original statements, & show how they calculated the dollar amount they say you owe, in some states collectors must be licensed & bonded to collect (check your state laws they are online)
10) it sounds to me like a junk debt buyer purchased your bad debt and is trying to get you to pay triple the amount they paid which is pennies on the dollar.
11) once you receive the (green card) certified mail return receipt signed by the collection agency, dispute the tradeline with credit bureaus again. or ask for a reinvestigation.
A) at this point the credit agency has to mark the tradeline as in dispute or they are in violation.
B) the credit agency has to provide you with adequate validation of the tradeline within 30 days or cease and desist all collection activity.
C) that means they can not verify with the credit bureau that tradeline or they violate.
D) if they do not verify with the credit bureau within the 30 days under the FCRA the credit bureau much delete the tradeline
E) it's a catch 22 verify & violate or don't verify & delete
F) you might want to google Hipa laws concerning credit reporting. Hipa have specific rules on reporting medical bills, you might try that route also.
good luck!