Incapacity to service car

Hi, I have had the most displeasing experience with Bosh, Hatfield in Pretoria. My car (Opel Corsa Lite 2008 with full service history) was brought in 2 weeks ago for a service, among other things I was told the clutch kit and the throttle position switch needed to be replaced. Five days and R10,000 later I got the car back with an engine light permanently on, the speedometer unresponsive and issues changing gears. Brought the car back and got it back 2 days later with the dashboard fixed but still issues with the gears. Brought the car back again and was told the engine mounts and gear shift cable now needed replacement too. Another 3 days and R4,500 later I got the car back, and it is now impossible for me to get in 5th gear or in reverse gear and will have to be brought in again.