Unsafe second hand car and empty promises.

I bought a 2004 Volvo xc 70 from Matchbox auto. It showed 157000 kms on the clock. This car is totally unfit for use. I had it checked out at Dekra and they identified a leak on the steering, among other minor problems. According to the dealer this has been fixed and it was only residual oil on the chassis that they would clean. I drove it for 100kms and a number of service required messages appeared on the computer. The gearbox was clunky and I complained about this as well. The dealer took the car back to fix the warning messages and the gearbox. The engine warning lights came on again and I took it to Volvo to reset. They did but different warning messages keeps on appearing. The gearbox jumps now into neutral when ever it has to gear down. Volvo also confirms that the steering is still leaking and quoted R16000 to replace the steering rack. The dealer is not responding to my emails asking for a resolution and after talking to him once on the phone is now not answering when I call. I am convinced that the car did many more than 157000 kms. I offered to trade the Volvo in for another vehicle, but still no response. i obviously have been duped.