Same thing happened to me the guys in my parking garage like to play bumper cars, I do have a pretty thick bumper guard that wraps around the bumper so there aren't any blemishes on it. Took it into the dealer and they admitted that the clips that hold the bumper on are subpar, obviously I'm not the first to complain about this. Luckily I'm still under warranty so they ended replacing the entire bumper. If they do it for you inspect their work after, they ended forgetting to replace the bolts that hold the bottom of my fender flares to the inside of the wheel well.