Maybe you could get the school to waive the requirement that you live on campus. Granted that is not what you want but it does not seem fair that you can occupy a 2 bedroom apt. when space is at a premium. The school did offer you an accomodation but you did not accept it. They have met their burden. They do not have to keep offering accomodations until they find one that you like.

Consider asking for a waiver.