Mercedes Benz refuse to assist with their faulty vehicle

purchased a vehicle directly from Mercedes Benz in February this year,A month later the left front passenger airbag just deployed while I was driving.My insurance concluded that’s it’s mechanical issue. To date Mercedes Benz SA refuses to take accountability. Mercedes Benz Malmesbury did not disclose any defects or inform me that the vehicle was previous involved in an accident-That’s *****!! I don’t care whether I bought the car from a Cape Town dealership,the point is,it is YOUR dealer that deliberately sold me an accident vehicle and chose to hide that the car was involved in an accident even when I asked about scratches etc,I was told nothing is wrong with the car just cigarette lighter needs replacing-that’s *****ulent misrepresentation and breach of the sale agreement. The very same dealer is not taking any accountability and since I called them in two weeks ago,not a single soul has even tried to reach out. I’ve called many times and nobody is taking my calls- how pathetic!!