Breaking The Law

I bought a 2011 Audi Q7 3. Tdi from this company. On delivery, the one owner, Jogi (not sure of spelling) wanted me to sign a letter which says that I wave the six month consumer protection warranty that he must give me by law. I refused to do this, on which he than cancelled the deal, got in his car and drove away from his own shop. I drove 400km from Nelspruit to fetch this vehicle. I phoned his brother 10 times to see if there was anything to save. He did not answer. This is three weeks later and no reply. Dealerships like this need to be taken on for going against the law.