Dissatisfied service from Dollar thrifty car rental

I rented a car with dollar thrifty, after a day returning it they phoned to tell me that the car is damaged and they emailed me a claim form,but I asked if I can come over to their offices to check at the damages before signing, they agreed and they showed me a fender that was resprayed that I know nothing about and they phoned their tracking department to trace if the car was involved in any car accident and which panelbeater was taken to and the lady said she will forward me a tracking report and I'm still waiting for it but instead she e-mailed me a quotation of R31,270 for me to fix the damages