Parking sign fell on my car and dented it

Hi, I was at an event that had two parking lots managed by two different companies. I was in parking lot A and the parking sign belonging to parking lot B fell on my car. The base of the sign's post was rusted. I took some pictures showing the rust and the parking sign on my car. I only have a toll-free phone number of B and it is a big company that manages several parking lots.
1. How do I proceed with this?

1. Would my insurance go up if I place a claim with my insurance company.