Botha and Deysel Executive Motors-Contract cancellation

I bought a car from Botha and Deysel Executive Motors on the 31st of December 2021 which MFC is financing. My sales person was General which I don’t recall his surname. I took the car on the 31st and bought back after as I was not happy with a sound coming from the engine. I have proof of whatsapp messages fighting to get the car back and getting a service book as well. It was then fixed 2 weeks later after reporting to the dealer. I drove the car for +-6 weeks and on the 05 March 2022 the car did not want to start anymore. I had to use my own money and resources to get the car to the dealership. Upon arrival the manager Armant said he did not know about the car been on the floor of his dealership. My question was how is it possible that the person who made sign let it happen knowing well that the manager does not know about the vehicle, unless there was foul play. So to only discover that the so called sales man was fired due to dishonesty towards the dealership. I request cancellation of this contract as i am paying R4000 for a car that I drove less then 6 weeks. I also request MFC to deal with this dishonest dealerships which give them a bad reputation..