BMW sold me a car without disclosing that it was previously involved in an accident

I bought a pre owned BMW X4 20D M Sport 2019 in 2021 at SMG Durban. I just found out when I was trying to sell the car that the car was previously in an accident and had the front door replaced. This was never disclosed to me at the time of the sale, in fact this was not even on the car's records.

This dealership does not want to own up to their mistake. The Manager, Mr Ry-Lee Ronelly say they are sorry that I was not told of this and they will sort the problem by buying the car back to them at a trade value, which is far less than what I still owe the bank. I think and believe the contract between me and them is null and void as I accepted the deal with false information. They are refusing that. I believe I bought the car at a higher price as the accident wasn't taken into consideration when pricing the vehicle. I am prepared to take this up. I trusted their product only to discover that I was driving a risky car for 17 months.