poor customer service

upon the return of a rental car was told there was a rear dent which i wasn't aware of since the car was dropped of, fine i see it and was told to sign to have they insurance assess it, a month later a letter saying i need to pay them R4500 is sent , were as nothing was said during the entire month. today i receive a harassing call from they head office saying i need to pay it doesn't matter that the branch never got back to me, the agent was rude and insisted on speak SeSotho thou I was responding in English there was really a poor display of phone etiquette.