Incorrect information

My car was towed to Peugot Fourways and I was made to sign forms that I was told where to note that I was leaving my car at the dealership.I was never informed that the forms where me accepting to pay a diagnosis fee.i informed them that I would not be repairing my car there,I was then informed of the diagnostic fee of r750.They told me I signed to accept that I would be paying,I tried to contact the dealer on several occasions and then I went there and I was accepted rudely and retailed and informed them that I would not be paying as I was not informed.The gentlemen who made me sign the forms even admitted that he did not tell me and that I would have to pay as it doesn't really matter that he did not inform me.I called a sales agent a while back Brian and asked if I would have to pay anything with regards to my car being there and he advised I would not.The gentleman at the towing company is also my witness as he was there when I was told that I would be signing documents to acknowledge that I'm leaving my car there and not anything else.Had I been informed of the fee,I would have paid or made an arrangement to move the car elsewhere.