Poor service delivery

<p>I took my car for service at Renault Centurion on the 22 of December 2016. When went to fetch my car it had gone from 30 000km to 300 000km I was told by Andrea that it was a mistake that they were made aware of after they had serviced my car, however he promised me that I can go on holiday and he will give me a call before I'm back once they have the equipment to reset the ****os. I did not have a problem as this was the second time I had gone to Renault Centurion to service my car and there was no problem. Just when I was on my way home I realised that my USB slot was not working, on top of that when I start eccelarate my car it keeps pulling me back. The next day I went back to Renault Crnturion to explain this and I was told that I should not worry, I must go enjoy my holiday and before I know it they will call me and sort out my car. It's been 3 months now and I don't know how many times I have called them and every time I am told that Andre is busy with a client and they will tell him to call me back. I don't want to wAste my time and go there as I have done it before twice already and I don't want to call again as I am not getting any assistance. Today my car is on 306500km , I can't play any music from my car and it is still pulling me back and requires me to reduce speed. I don't know who I need to talk to or contact before this gets sorted out but I am tired of waiting. I need assistance ASAP</p>