Bad customer service

Rented their c class through Mercedes Benz on call, whilst driving on the road an on coming car passed me and a small stone hit the windscreen and it scracked. I took pics and send it to Woodford and explained what happened, I was then adviced to bring the car in for an exchange. However on arrival I was told to pay the full amount of R12,500 to replacing the windscreen first before They can give me another car, when I asked if the vehicles are not insured so that I can pay the access amount, I was told they are but I still have to pay the maximum access amount. I was forced to leave the car and take a taxi because I couldn't pay immediately. I won't be using their service ever.