Bill is correct all the way. I've written about PRA on this site many times, but this thread should give everyone a pretty good start in raising proper disputes and deflecting this agency's abuses:
If PRA or any other agency thinks you owe something, be sure to respond on real paper to its federally required dunning letter with a dispute and validation request, adding that you either restrict or revoke consent to call again. Given the industry's documented need to break laws to get at your assets, you should dispute even if you agree slightly with its claim.
If the account is not legally collectable, or it's simply not you they want, you're free to send a full cease-comm, cutting off all contact. Send all notices via USPS Certified with return card. The FTC and many consumer watchdogs explain how to draft them. Pay close attention to all communication and document it well. If those contacts yield legal violations, you may collect from *them* through a judge or arbitrator.
Learn how to exercise your FDCPA rights as an alleged debtor at FTC-dot-gov.