Quick on selling but BAD on service

I bought a brand new car NP200 in May 2015.Themba Maphumulo was my sales man, He sent the car quickly than I expected with out a radio,i signed the contract stating the amount of radio 2500,after 5 months I received a radio cheap radio,its not even in stock anymore, I phoned Themba and asked how do I install the radio because the car was suppose to come with a radio from the start, He told me to pay for installation and send the proof of payment to Tricia which I did months ago, as from then he's is not answering my call nor smses,and Tricia does know anything about repayment. Even the service book I received it last week. Six months is over for a service!!NO COPY OF CONTRACT!!Nothing<br> <br> I even gave them customer and he promised a commission till now nothing!!!