Both joint credit account holders remain liable on the account until the debt is satisfied or otherwise discharged.
When married joint account holders get divorced, the following factors may be relevant:
The terms of a divorce decree are separate from the legal obligation of both parties to repay the debt under the account agreement.
Although the creditor may agree to release one party, it is not legally required to do so.
You may want to seek legal assistance to address any remedies available to you.