Selling damaged cars and does not disclose

I bought a car at Aucor Auctioneers in Centurion 2 months ago, after receiving the car I had to take it to Dakra for inspection and roadworthy where it did not pass I was told the car has oil leaking. After that I proceeded to take it to Mercedes Benz where I was told the car was involved in a car accident and I need to pay R240 000 to fix it. Upon buying the car they did not disclose that it was involved in an accident they just sold me the car. I asked them what is the way forward on this matter they said nothing they can do but sell the car to someone else and they have not. I am liable to pay monthly instalments on a car I don't have and they are doing nothing about it.