very bad service delivery

i took my car to Bosch Service Centre in Silverton after it needed replacement of some engine parts. the warranty paid R 20000 for the repairs and i paid the remaining R 10026. weeks went by without getting any feedback from the people from Bosch about the progress of the car. i went to them on Friday the 29th of June to check for the progress and they told me i will get the car on that day,i stayed there till 4.am waiting for them to finish up. Still the car wasn't done. as i was supposed to leave to Zimbabwe due to business purposes and they said that they will deliver the car to my place on Monday the 29th June or Tuesday the 30th of June. i am still waiting for feedback from them and i am the one who keeps calling them. they promise to call but they never call. i am so disappointed with the service that i received from Bosch Service Centre in Silverton. i will never ever take my car there again and i will not recommend them to anyone. instead of fixing my problems they have created more