Europcar south africa.. shame on you.

I made a booking in august for december at cape town airport. I have the printed reservation with a total of R1043.40 made on august 16 at 15:57. When i logged into my booking today the price is now R1500. How the hell is this even possible? When i call customer care...no answer... call head office they redirect me to customer care which again ...no answer. Do i deserve to be stressed out like this before my december holiday by a so called professional car rental company?