Is there excessive weight in the car, and are you towing anything? Do you have a pulsation when braking? Maybe the brakes aren't completely releasing. I'm not sure if you have a floating or fixed caliper system, but I would verify the pads are moving freely in the guide pins if it's fixed, and if floating make sure the caliper slides freely for floating style. Beach Town, and oxidation of brake hardware can equal trouble. In New Jersey "Lemon Law" is 3 times back to the dealership for the same complaint. Don't feel so bad, I've seen brakes go on Mercedes as low as 6000 miles.
Good luck
jv