Trunk Lid Lock problems of the 2002 Mercedes Benz C320

I own a 2002 Mercedes Benz C320 with less than 55,000 miles. On sat. Aug. 20, 2005 while opening my trunk with the remote I heard a strange sound coming from the trunk assembly. The very next day I went shopping and went to place my items in the trunk and heard the same sound again. This time when I go to close the trunk it would not latch. I call mb 1-800 service, however, they didn't want to come because they were not sure they would be able to repair it and still have to charge me for coming. So I then had to try to hold the trunk down with what I had in the trunk which wasn't much. While traveling on the freeway the trunk lid sprung open which to me was very dangerous because I had to try to maneuver my way across lanes of traffic with a trunk lid up blocking my view. I took the car to the dealership and the service guy himself said he did not know why the assembly broke. The trunk is not something one uses everyday so I do not understand why it broke especially considering the fact that the car is 3 years old. This simply should not have happened. Also, I checked the different mb forums and it appears that others have had some form of problem with their trunks along with a laundry list of other malfunctions. I now have to pay $ 350. 00 parts and labor for something I believe is a manufacturer defect.