Golf TSI118 shudder

My dream of one day owning a VW Golf has quickly turned in to a nightmare. My 2010 Golf TS118 developed had a shudder early in the piece, which I thought was the way I was driving the car, but in July 2012 it became apparent there were big problems brewing with lots of warning lights - catalytic converter, engine missing, more shuddering, and lack of power! ? In August, at? 21,943 km VW replaced the pistons, injectors and associated parts under warranty. I was told by the dealership that despite the engine problem Volkswagen would not replace car, just in case I was thinking on those lines. ? Last month I took the car back after I'd experienced some shuddering over the last couple of months. The engine was tested and deemed safe and I could continue to drive it, but soon after wards it lost power and was missing at high speed. By the time I got the car to the dealer the problem had disappeared. I left it there for further investigation. I intend to lodge a complaint with Volkswagen, and ??I will write a letter to the CEO of the dealership and try and do a deal with the dealership to get out of this into another that is model not having the same problems for the least possible money? ??What else do you recommend?