Selling Accident vehicles without tellong buyer

We bought a car from Wiz White Motors, and found out 2 days later that the car was in a major accident, and was repaired very poorly. We approached the so called dealer and they refused to refund our money. How could they have put car through test to register if in such a bad state? We can't drive the car, it is not roadworthy at all. Do not buy from Wiz Cars in Kempton Park, they sell accident damage vehicles and don't tell consumer. They should be investigated, this can not be legal??