Transfer Case problems of the 2007 Mercedes Benz E350

In 2011, I purchased my vehicle from a dealership as certified/preowned at 46,717 miles. Regular maintenance was kept up at the dealership. In 2015 at 74,563 miles, I brought my vehicle in for 2 problems: a check engine light had come "on" and my vehicle was experiencing vibrations from the power train when turning and shuddering when making sharp turns at low speeds. The check engine light was a result of a balance shaft engine problem which was, at the time, in a class action suit regarding this problem for these vehicles. The manufacturer agreed to pay a portion of my repair for the balance shaft issue. The second problem turned out to be a transfer case issue. The dealership stated I had a bad transfer case and they recommended I have the transfer case replaced. At the time, I could only budget myself for the balance shaft repair and 4 new tires. The transfer case oil was changed which slightly improved the vibration/shuddering issue. I currently still have this issue more severely and require the transfer case be replaced. My vehicle's transfer case oil was changed at 30k miles by the previous owner. Through research, I have discovered that in January 2009, a manufacturer bulletin came out that specified my vehicles VIN number was included in the stated problems with the transfer case. They had installed defective transfer cases at production in 2007 and should remedy this! I have spoken to the manufacturer and they will only pay 25% of my parts for this repair which leaves me with a $3200 bill for a problem they knew about. On many occasions, while waiting for my vehicle to have maintenance completed, I over heard service representatives speaking to other customers by phone or in person. The service reps indicated in many instances that the problem the customer was having with their vehicle was due to the transfer case. These transfer cases should be recalled!.