They damaged my car

On the 16th of Dec Saturday , i took my car in for a service at Bmw Clearwater .my car was in a drivable condition it didnt even have any warning signs on the dashboard,i wasnt even offered a shuttle service , had to wait for my car at their premises, once the car was completed, i drove about 2km and the car started giving issues, the likes of misfiring , drove the car back to the dealership, i was told one of the coils had a crack , however it was replaced with no charges implicated , the very same problem continued the same day then on the 18th of Nov which was a Monday, i towed the car back to them , i was told that everything had been thoroughly checked, the only thing that was at fault were wires that had been eaten by rats, trusting them i gave them go ahead to fix the wires at addition R3000 .i was promised that i would receive my car on Tuesday as they had to order parts . Tuesday afternoon the part was fitted but the problem was that the car wouldn't start , they took the car to another technician , the technician advised that there is a certain part that is damaged that caused the car not to turn and or even drive . Took the matter to Kobus - who is the Client Relations Manager whom didn't even help then i further took the matter to BMW SA, now im told that they willing to go 50/50 , which im not prepared to pay cause when i took first took the car in on the 16th it was in a drivable condition. And it only required a service . I REGRET EVER BUYING A BMW, they only care about sucking their customers monies .