False advertising, incomplete build trailers

I bought a new trailer for R38 500.00 cash. On the day of delivery, I was told there is no spare wheel or jockey wheel included, according to them it was an optional extra. I was not informed about this on the day of the payment for the trailer. I had to buy a spare wheel and a jockey wheel myself, which cost me an extra R1935.00. This car trailer's weight is 780kg. It is impossible to handle this trailer without a jockey wheel. They cheated me. I phoned the owner Mr. Jorrie afterwards, but keep on telling me that this is an optional extra and that he cannot give me a jockey wheel. According to the law, all trailers must be fitted with a jockey wheel. Without it, it is not roadworthy.