sounds more like a mechanical problem than a software one to me. It will still be under guarantee so ring the store and see if they have a local branch.
Did they install it for you? if not make sure you dont take any crap from them about guarantee only being valid if installed by a qualified person, it's a pile of crap salesmen use to get out of doing an exchange (I promise I never used to say things like that honest <img src="rolleyes.gif" border="0"> )