Back door locked solid
 

Can anybody help me with this one please. I have an '02 Passat Estate and the O/S back door wont open from inside or out. Sounds like the central locking eventually ground to a halt and the mechanics re the door lock are in operative. I've removed the trim panel and the inner steel panel ensured the rods are in the right position and still the door wont open. VW agents advise they've got to "break" it, what ever it is. By all accounts it's not a common occurance but it is menu priced at approx. £200 quid. All other doors are fine, any ideas would be most grateful.