If I understand my state correctly, it doesn't matter whether I'm on the card or off, a user or a joint holder, I'm legally half responsible for any debts incurred while I was married, unless the divorce decides otherwise. Still, the only way the divorce can decide this is to order payment to the card company for my "half".
Sounds bizzarre, but one could never guess who charged what and why.
It seems the more important thing here is that the cards are frozen and payed off. I would have thought the judge would have ordered that. I would give it a shot anyway. Ask your ex if at the very least he would be willing to call them, ask that the card be frozen, and a new card issued just for him. I doubt they will take you off the old card, and if I were that card holder, I would think it was an attempt to not be responsible regardless of what the judge ordered.
Good luck!