Did they give you an est delivery date? And has it passed yet? If so you could try using the 'missed delivery date' avenue ... If you used credit card then perhaps you could dispute it.
Also read the fine print to see what the paperwork says about restocking. If it's vague you can try pushing back on the restocking fee. Like Term said, how can they charge restocking if not delivered? Personally I'd have a problem with that one.. but maybe its spelled out.
If you really want out - don't roll over on the restocking line. Sounds to me like these guys follow the high pressure timeshare sales model and would say anything to keep the deal alive.