I established a cellular phone account with US West Cellular (now know as Airtouch) in 1992. In March 1994, I began receiving phone bills for a phone number that did not belong to me. I immediately notified Airtouch. The account was finally corrected and when I transferred my account, the account was paid in full.
After I transferred the account, Airtouch apparently charged off a "balance due" for the calls that belonged to someone else and sold my account to a collection agency that is now showing on my credit report, twice. Once from Airtouch and once from the collection agency.