Hayes Motors will ***** from you

I bought an Isuzu from Hayes Motors. I had several complaints about the performance of the vehicle. Less than three months after purchasing the vehicle a piston broke. Hayes Motors offered to replace the engine with a new one and I was to pay R4000.00 towards the new motor. I paid the money as agreed. after receiving the Isuzu back I still had complaints as the vehicle was not right. less than 10000km later the piston broke. I took the vehicle to a mechanic of my choice. I was informed I did not have a new motor in my vehicle. the diesel pump was old and needed repair as well as the injectors. I phoned Hayes Motors and informed them of the problem. I was told they did me a favour to fix the vehicle. on request Hayes Motors could not provide me with any detail of the work they have done on my vehicle. I feel Hayes Motors placed me under a false to prevent me from returning the vehicle and to get R4000 from me. the vehicle has cost me more than R30 000.00 above what I had paid for it. on a statement that I feel I should take this to court I was informed by the dealer principle that Hayes Have the best Lawyers they are not fazed.