Sold me a R219000 car with worn tyres

I bought a R219000 BMW 330D cash from Hyundai Menlyn (multi-franchise) around the end of January this year. Driving home after taking delivery, I contacted Ronny (salesman) to complain about a noise from the front wheels. He agreed that I could bring the car in upon my return from Cape Town. The noise got worse and I took the car to Tiger Wheel & Tyre in Claremont, Cape Town. They pointed out that the right front tyre was unevenly worn and had some damage which caused the noise. In addition, they pointed out that all 4 tyres were worn and needed replacement. Wires were starting to show on the inner part of the rear tyres. I went to Super Quick for a 2nd opinion. They told me exactly the same and made it clear that I would certainly risk my life driving back to Pretoria with those tyres. I acquired 4 new tyres from Super Quick (cheaper than TWT). I called Hyundai Menlyn from TWT to inform them about the situation. Afterwards I took the payment receipt to Hyundai Menlyn and even said they only need to compensate me 50% of the cost as I do not expect new tyres on a used car. I thought that was very reasonable on my part. They now refuse to talk to me. Please assist.