Coleman Buick GMC

I brought my vehicle in to have the windshield wiper pump looked at. I received a call that the dealer took it out for a test drive and informed me that the control arms were out of spec and needed repair. I don't know how or why a test drive is necessary to test the wiper fluid pump. Service Tech didn't give me a straight answer. This would raise the bill from 600 to 1600 dollars. I declined the control arm service. I also had a coupon for 25% off all service. In my opinion, for a 600 dollar bill, I would get 150 dollars off. The service tech said it was removed from "Labor" but couldn't show me how much labor was actually put into the vehicle and only took off 50 dollars. Eventually I got it down to 100 dollars off but never the full 150. The service tech first indicated it was only off of parts to get to the 50 dollars. Then the service tech indicated it was only off 1 of the services performed...not all the service performed. No where in the coupon did it state any of this. In my opinion, I felt like they did everything they could to not honor the coupon. Finally, the moon roof service was not done correctly and I have to bring it back. As soon as I get this all straightened out, I will do my best never to patronize this dealer ever again.