Disgusting service

I took my VW Polo Vivo in for my 105 000 km service. My car was in perfect condition prior to the service. I fetched my car after work and noticed a terrible sound. I reported the sound at the branch were the service was completed and my car was booked in again for a check up today. Autohaus Centurion refuse to take responsibility and claimed that my car's gear box has given in. My question is why would it give in right after the service was done, and that I was not notified of the gear box during the service or when I fetched my car from the branch. Instead I now have to pay R5000+ for them just to check what's really wrong with the car. Worse of all it seems like more damage was done cause now the car smell of smoke like burning wiring or oil when the car is on the move. Is this how you treat you loyal female customers? I'm disgusted... Since I trusted that you would provide a better service. It's disgraceful how one needs to fight just to get something right which was broken by your technicians, and now the blame is being shifted. You put my life at risk as well. I am taking my complaint to the newspaper since Volkswagen can not be trusted and seems to be in the business of robbing people in an ******** manner