Did you get contact info from any witnesses if any were present at all? My family was also involved in a fender bender recently and we won our case despite the fact that it was on private property (parking lot). As long as you have someone to testify for you, there is always a chance of turning over a 50/50 ruling.
edit: oh and the 24 hour time limit is flexible, just call and explain your situation and they’ll usually be understanding. I had an accident early this summer, and i thought the “limit” was 3 days, i paniced when i heard it was 1 day but the collision center was very understanding and i reported the accident 4 days after the actualy time of incident.
No witnesses. If i report it will they be taking pictures of the car because my insurance will neglect me with a whole shit ton of my un modified car…Engine swap, wheels, BBK, exhaust intake FMIC, Gauges, lowered…etc…