Bad service at Webuycars

Bought a car on Monday. It started overheating hardly 10km away from the dealership (Webuycars). We stopped at a garage, cooled it down. Got on the highway and the car started decelerating. Phoned the sales person and told me to try driving, should it continue to give me problems I should call the customer care. Had to wait at a busy N1 North with the kids for about 2 hours waiting for a tow truck.