Tata Motors — Poor servicing and extracting money by damaging other parts during service

Address:

AM MOTORS NARWAL JAMMU

I have been going to AM MOTORS JAMMU for 2 yrs now and every time after the service there appears to be a problem with my car and I have to bring it back to service station and they repair it with extra money. The problems that appears were not there before they take the car for initial spin. On 18th June i took my good running car for servicing n before leaving the station. The AC started creating loud noise which wasnt not thr when i brought the car and they checked taking an hrs time n said a part need to be put and have to come from stores.
Now I'm without an ac in car at this summer time..plz help me raise this issue and get my car ac working without any cost as it wasn't thr when they checked innately. How did it appear during the service.
Kindly help