Let's face it
If you enjoy owning and driving a Benz then the best advice I can offer is to educate yourself on repairs of your new found love. Dealership maintenance sucks, let's face it. Either take your car to an independant that know's what they're doing or do it yourself. You'll find yourself going broke, unless you like that feeling, if you don't. Find a reputable independant that most likely has twice the knowledge and hands on experience that will tell and or repair what is actually wrong with your ride instead of hiped up billing that you have recieved. The BBB would be my first recourse of action if I got screwed as I have read here on this post.
P.S. Another DIY that is tired of folks being taken advantage of.
"Tell me and I will listen, Teach me and I will learn, Show me and I will accomplish, Involve me and I will succeed."
'84 300SD 256,000 Gold on Brown (Mileage Award)
'86 300E 246,000 Blue on Tan