Divorced, Paid my half of the bill. EX filed bankruptcy and bill collectors are coming after me. what can I do?

You are not allowed to discharge in bankruptcy court debts assigned in a divorce decree, under the Bankruptcy Reform Act of 2005, at least, not in a chapter 7 bankruptcy proceeding. If the discharge has not been issued, you are well advised to hire your own bankruptcy attorney to file an objection to her attempt to discharge these debts as part of her bankruptcy proceeding. If there was a hold open on maintenance in your divorce decree or other language under the debt section that you could go back into court to enforce the decree if either party goes bankrupt, consider hiring as well, a family lawyer, to take the case back into family court. If the bankruptcy is pending, you may need to seek relief under the automatic stay, to file your motion in family court.