If these are ex-Germany tickets I would assume it ends up in a German court. They have a history of shredding unfair airline terms and conditions, Lufthansa got a bloody nose a few times (they got a beating for just assuming that a ticket should be flown in the order in which it was ticketed).

As for closing down accounts. I wonder if BA would really send a CCR card holder to the competition over a missed segment. But ultimately it is their call and business judgement.