Vanns states that iPads are not returnable. I agree with you, though...Essentially when purchasing from Vanns, you are stuck with the iPad...because Apple will not refund the money you paid for the iPad to Vanns either.
You may have some wiggle room in arguing that when you click on the RETURNS POLICY tab on the iPad page, there is NO mention of an iPad not being returnable if opened. The only place this policy is stated is if you click on the general Returns Policy tab at the bottom of the page. Their site is inconsistent and incomplete in parts.
The first email I got from them said I could return it within 15 days, the second said I couldn't. So, the customer service people don't even know.
I have an appointment tomorrow morning with Apple, hopefully they'll have some in stock for a replacement.