First, file a formal complaint with the Dorm super, the staff and the Dean. Tell them, in no uncertain terms, that you will go to ever newspaper and television station in town and scream bloody murder if they don't do something.
That is an intolerable situation, one that you should not have to put up with.
On a side note, its times like this I am glad I have a son instead of a daughter. I can smack sense into a son but I would look out of place guarding my daughter with a shotgun while she showers in the dorm.
