Without knowing the circumstances I would call Marriott Rewards to verify that this is indeed correct. IN 2009 my account information was stolen by persons unknown to me, but fortunately they did not attempt to cash in points from my account or buy items using points, or stay using points. They did cash checks using my name and no ID but that's another story.
So, please call Marriott Rewards, the explain the situation, and see if it can be fixed.
I had to do a lot of things to get my account reactivated and renamed, including providing a notarized letter to Marriott that I was telling them the truth and that I was not attempting to cash checks fraudulently.
Good luck and let other Insiders know what happens.