My response:
As you know, BK "trumps" State law, and the Marital Settlement Agreement. The Ex either doesn't realize this, or knows it but is merely trying to put off the inevitable. Since the creditors are calling you "based upon" the Ex's information, all you need do is remind them of your BK, that they were included, and to please make a note to stop calling you.
Once the creditors get tired of the "run-a-round", they will eventually smarten up and sue the Ex. And no, she cannot sue you, and win, for the debts that were included in the Settlement Agreement - - remember, that agreement has been "trumped" by Federal law.
Once she's sued by the creditors, she will undoubted attempt to Cross-Complain (countersue) you based upon that Agreement. Your BK "discharge" is your Affirmative Defense, and the ultimate defense. You'll be able to Demur to her Cross-complaint and have any lawsuit she files dismissed.
Oh, and one last item. Speaking of "the inevitable," when she realizes that her "maxing" out the cards is going to fall back on her shoulders, she's going to have a crap fit !
It may have cost you a BK, but isn't revenge sweet?
IAAL