I bought a new C300 4MATIC one month ago in Ontario, Canada. A week ago I first started to hear a squealing sound (similar to worn breaks) from the right side of the vehicle on acceleration. A few days after that, I started to experience a power loss on sudden acceleration. My speed at the time of acceleration was about 50Km.
I took the car to the dealer and after investigating they have indicated that the transmission was leaking from the o-ring seals. They believe that was the cause of the power loss but they are not sure whether or not it was contributing to the noise.

The dealer has indicated that they have changed the seals and that the car leaked about 5 quartz of fluid. Could this have a serious negative long term affect on the transmission? Should the dealer follow any steps to minimize further problems that may stem from this? Such as a fluid flush?

Has anyone else experienced similar problems, especially with such a new vehicle? I find this to be unacceptable for a new vehicle and would also like to know if I may have any grounds to push for a new vehicle and the relevant process?