Autohaus on Edens

I bought a new 2008 C Class in 2008. I started having service problems immediately. I paid $150 for the invisible door protector & 4 weeks later it started to peel off. I called the service department & they said too bad it is done by an outside service. I called my salesman & he said that the service department is wrong & gave me a number to call. The outside service people came to my house & fixed it. The Autohaus told me that they do car washes 6 days a week. What they did not say at the time of purchase only if it is above 35 degrees however cars being serviced no matter what the temperature do get washed. I paid $595 for paint protector & now cannot get it washed at Autohaus even though winter with the salt on the road & all over my car is the most important time to wash my car unless it is 35 degrees. They now have a number I can call to check if the car wash is open. I called & they said it was open. I drive out to the Autohaus & there are 2 signs saying the car wash is closed so I go in & ask why. I am told they are only washing cars that are being serviced. Sure the cheapest service is $388 that is the A service. However they reluctantly washed my car. The latest was a free inspection. I just received a discount coupon for new wiper blades. 2 weeks later I go in to get my car washed & get the free inspection. The inspection report says my wipers are streaking. I am thinking me car does have even have 19000 miles on it & my wipers were not streaking. I bring the car in for the B service & ask the service consultant to check my wipers. He said all the needed was cleaning on the bottom & not replaced. He stated they last 30,000 to 40,000 miles. They charged me $2.50 to clean the wipers that sure beats $75 for new ones. I then showed him the report & he had no answer. I asked why did the report written by a technician not recommend cleaning? The service advisor had no answer. I have called the service manager Peter Laskowski left a message & he will not return my phone call. I asked the service advisor to have him call me this was 4 days ago still no call. This is the worst service department I have ever dealt with in my life.. I have a great reliable car. This is my first Mercedes but not my last. When I but a new one next year I am going to find a dealership that cares about their customers