Snap on cases affecting MacBook Pro

I recently purchased a snap on case for my MacBook Pro that I just bought and I've noticed that after putting the case onto the screen half of the computer it feels "looser" and closes w/o me pushing down on it. So my question is, is the snap on case affecting the hinges of the MacBook and weighing it down, and if so should I still be using it, and is there a repair for the hinges at the apple store?