what insurance compay are you with?

its plain and simple, excess of 500 applys until the third part admits liability or is held responsible for the incident.

To be honest you should just let your insurance complany deal with the police and responsible party for you, (you pay insurance for a reason). as long as you dont get your car repairered you dont need to pay your excess, excess should only apply if your car has been repaired or if liability cannot be determined.