INCOMPETENCE SERVICE AT Toyota Melrose

Took my car for a major service at Toyota Melrose on 24 November 2017. I dropped off my car at 6:45am and collected it at 17h30. The service advisor contacted me and advised on which parts needed to be changed, the actual work and cost of which I accepted and gave the go ahead to proceed with the service.The invoice came to over R10000 which I paid on collection. The car was driving fine prior to the service and when i left the car would cut off while driving. I thought it was something minor until it stopped and could not move anymore. I got stuck within driving 50kms from the dealership where the car got serviced. I got stuck on the highway and my car was towed to Toyota Menlyn off which they refused to fix and have a look at. The service advisor at Melrose say the is nothing they can do as they don't know what happened. They say they don't have a solution to problem, Menlyn has not worked on the car and i am expected to pay Menlyn to look into the problem and fix it. Car was fine prior to Melrose they took my R10k and now the car isn't working or moving at al