a deaer sold me a damaged vehicle

I bought a Audi 1.8t a 2002 model,which gave me a problem after two weeks of being a new owner.it was smoking in a very bad way and took it back for them to check it up,I left it in the morning to a manager Tiaan Viljoen and went to work with an aim to get it afternoon to go home with indeed I went back to fetch the car and they said it was fixed, I took it and went home on my way I was so surprised to see the same thing happening from that day it was me bringing the car in the morning and taking it afternoon for three to four days then ask for another car but that wasn't a success nor an explanation as to why am I not getting another car but I told to use it like for a week I didexactly that as I was desperate for a transport unfortunately in the last day of the very same week I had an accident that Mr Khumalo could not stop at the streetlights that had stopped me and he knocked me at my rear left hand side we towed a car to panelbeaters and fixed it and I reported a matter to a dealer.Now they do as if I reported the problem after my accident they don't wanna give me another car cause the one they sold me wasn't in a good condition.