Fuel Delivery problems of the 2003 Mercedes Benz 240

After bringing to the attention of Mercedes Benz of tampa a problem/concern with hesitation one week after purchase of my c240, I was told to start the car out in second or third gear. Approximately one and a half weeks later my engine stalled in the middle of an intersection, as a result there was an accident which potentially could have been fatal. I then immediately took the car in for service, and was told the computer could not find a code/problem with the vehicle. The service department changed out the fuel pumps in the car after stating there have been problems. The car now shows a noticable improvement. After receipt of the car, I spoke with the general manager, who had the assistant manager call me from Mercedes Benz of tampa and I was quickly referred to the Mercedes Benz customer care line. After voicing my complaint twice, and put on hold twice I was then hung up on. Dt.