Unable to asses vehicle which was inaccident

I was hit from the back by vehicle travelling at high speed at 120 km on 21December 2014. On this day the assessor from Discovery has not yet compiled a report so that reperations can begin. According to contract I have a rental for 4 weeks, but everytime to get an extension costs me 5 phone calls and waiting on the phone for 20 minutes or more. The request for weekly extension on my rentalis then forwarded to management and a a same day \come back@ is promised. That never ever happens. It has happened that my rental was approved and then when Avis wants the car