Is there any after sale service

On the 4th of July this year i bought a AUDI Q5 from Webuycars Midstream branch and was told the car was in excellent condition with a full service record. The car was bought at 175 000 Km and is currently on roughly 178 000 Km. On the 15th of November the car broke down with me next to the road and had to be towed in as it refused to start what so ever.

With the 2 year mechanical warranty that you have to take at Webuycars and the process in getting them to repair the car as the damages came to around R27 000, we found out that the last service at 171 000 Km was not actually a service but a engine replacement. The car got fitted with a 2nd hand engine and was never disclosed or mentioned to me what so ever.

I did not buy a car with a 2nd hand engine in it and do not want this vehicle. Webuycars further more still want us to cover about R4000 of the damages and for me to keep the car. The car that could not even last 7000 Km with the 2nd hand engine before already costing that amount of money to get repaired and that they sold to me having me under the impression that there is nothing wrong with the vehicle. and it is in a great condition.

I do not want this vehicle and i cannot make it any more clear to them but getting no assistance regarding that. If not cancel the deal entirely a replacement vehicle is also acceptable.