Ex-wife reactivated account, now in collections

[aggiekat]

My fiancee's ex-wife has had serious issues with credit in the past. During the marriage, they had purchased an appliance at a large chain store on the in-store credit card. Soon after, they paid off the account, the cards were destroyed, and my fiancee called them to close the account.

Last Christmas, his ex-wife remembered the account, reactivated it (even though his name was on it and they were now divorced), had a new card issued, and used it to buy Christmas presents, running up over $550 on the card. He found out about the card, immediately called to close the account, and confronted her. She promised to pay the bill. In July, she went delinquent on the $10 bill, and it is now in collections.

He has been told by the credit card company that the divorce decree means nothing, and they are jointly responsible for the debt. All receipts are signed by her, and she reactivated the account without his knowledge.

The divorce decree didn't even mention this card because it was a "closed" account.

Can anyone recommend the best course of action?