Faulty car

I would like to report a situation where i bought a car in a company called exclusive auto in Pretoria, they sold me an Audi A3 2011. The same day i picked up the car it was 20th later on the day it gave me problems and i told them about it. They came to pick up the car the following day which was Thursday 21st. Now i want to cancel the hole deal/application they refusing and they want to fix the car. I will not take a car knowing it has been fixed. I need my R11k back. They can stall and fix the car but the sad thing i wont take it...I was almost in accident when it gave me problems what if something happened to me and now they telling me i dont have a window period after owning a car for 4hours shame...If i have to go to consumers Protection agency so be it. Because i am struggling to get to work as I am currently using my money for transport while i bought a car, I dont aant to negotiate but OUT!!!