Are you sure you don't mean lawbreaking Portfolio Recovery Associates? The name sans "recovery" appears to be for an innocent looking PR firm in Philly.
Most people do not understand that the DNC (do-not-call) list has no enforcement for collection agencies only telemarketers, that is the BIG loophole. The best bet is to take the advice here from others, first send a cease and desist letter, second file a complaint with your states Attourney General and then hopefully you can cath them screwing up. Sadly they can get away with legal harrasment until you notify them to stop.
Once again Do-Not-call lists apply to telemarketers not Collection Agencys, they will just laugh and keep calling. If you don't owe a debt contact your states Attourney General and file a complaint, the DNC people can't help you with a collection agent