Any tips on consumer law and old debts?

hi just spoke to good friend of mine (yes really) he was divorced and let wife keep house and pays child support as good man & for years rented accomadation, now just got small flat back on mortgage after 10 years of working 12 hours day & saving hard. A letter turned up out of blue from a company for a really old debt that was from 3-4 years ago, they have not been in contact with him for 2 years and he said what with divorce, renting & moving around and now finally feeling that he is in better place this has happened and he is concerned. I told him ignore but he said this is his home and he contacted them as he doesn't want bailliffs knocking. The company had charged way over top for the car at the time he had more than paid for it plus interest and he feels like its come back to haunt him , they asked ';have you got credit card debit card'; they want £3000.00 that's a lot of money. I said CAB but he said couldnt handle patronising? he's very proud man please only serious ansa's THANX