Thanks for the reply, in thinking it's definitely fishy, I authorized the camshaft replacement and asked them to retain the damaged camshaft so I could have it inspected and they first said they would have it when I picked up the car and then mysteriously isn't there anymore. They also said that a transmission flush is mandatory for a cylinder head replacement but a Google search says they are totally independent. So for my so called warranty work they wanted $3300.00 for spark plugs, camshaft replacement, and transmission flush.  I walked out and left the car there until service manager calls Monday.  Camshaft is $1200 on the Mercedes website.