Mister security guard was being an a**hole. Talking to his supervisor will only get you the same reaction. His boss will back him because he doesn't want an "issue". I would write a scathing letter to the head of the hospital including the security administrator. He is the guy who hired the man you dealt with or has hired the private company giving his hospital bad press. Unfortunately if it is a private hospital, bicycles can be banned and their insurance company might enforce this. Stupid...yes! It should be posted to be enforced.