The hotel manager was mistaken that he cannot resolve this. For stays that have already occurred, Marriott CS cannot help you other than telling the hotel management that they need to have your certificates corrected through property support.

I'm sure a Lurker here can help you in making sure a case is opened with the hotel informing them on what to do.

Also, as a general note to OP and anyone else: Don't book more than one room on points at once. Things like this may happen.