What can I do to get the information from a hit and run at a hospital if all of a sudden they don't have the security video?

I was parked and sitting in my van at a local hospital when a woman hit my passenger side back end while pulling into the space next to me. I turned around quickly to see her back up, and as she did I heard a crunching noise, so I got out of my van. She pulled back into the space very close to my van and when I intially looked at my van I only looked at the back bumper due to her car being parked so close to my van. There were a few small scrapes on my back bumper and her black car had a longer white mark on her left front bumper. The woman appeared to be in a big hurry and said "it is fine, it will wipe off". She walked quickly towards the door of the hospital. I was already late for my appointment with a specialist but I grabbed my purse and followed her to get her name and number just in case but she was gone. After hours of testing (3 1/2 hrs) later I didn't feel well and went home. I got up the next morning (yesterday) and saw that my back bumper was actually pulled away from the frame of my car and laying on my exhaust. I made a police report and they asked me to do this at the scene since it had been within 24 hrs. I also called hospital security about looking at the cameras and I was told that would be no problem since I had an exact time and they would get that to the police for me. When the officer and I pulled up I noticed that parking space she had pulled into next to me was for physician parking only. The officer went inside to get the security camera view and was then told they had nothing. This happened in the front of the parking lot and 2 parking spaces from the front door. I feel it was a physician and they won't help me to find out who she was. All I want is my bumper fixed. What can I do?