Should've thought about that one a little more then. Probably you could refuse it, it'd get returned to them, and you could get your ccard company to reverse the charge once you proved you refused it. Since you haven't technically received it yet, you could call the company and tell them you're going to refuse it and to refund you, they may just do it.
Edit:
Reading what you just posted, you may be screwed. Even if you refuse and they get it back, they can say that you still owe them, and keep shipping it to you. Since you entered an agreement with them for it they could technically go onto your credit report if you don't pay, not sure though.