Poor service report back.

We bought a VW Touran from them and had issues on the car with indicators and lights that comes on and off. The car went back a few times on our costs. Only once they put R200 diesel in. We are from Meyerton. They tried first to install secondhand parts and tried to let us believe it was new parts. I ask to get a report that was done the last time it went back but they don't respond on request. I also want to know if we have any guarantee. There is also a oil leak but they recon they spend already too much on the car. Service was very good in the beginning but very bad at the end.