You need to speak to them really.
You may have problems as it's not in the condition they sent you it in, but then again there wasn't anything you could have done to avoid it if they choose to package it in that way.
See what Scan say, if they say no, call up the Office of Fair Trading or an Ombudsman and they'll tell you your legal stand-point over the phone for free, and they'll sort it all out for you if you are entitled to return it and Scan still refuse.