Sears.com (electronicdealz.com) Did not get my Superpad in time for christmas, and still nothing. Internet

I ordered a large order from sears.com on Dec 14, 2011. I made sure that all my products would be here in time for christmas, well i received everything form sears.com in a timely maner, however the Superpad i order from their website that was a marketplace item did not come. this was a christmas gift for my child so i had to break myself and go buy another one. I called sears and cancelled it and they said they would refun me the money, however after calling seven times i was told the same thing at the end of the conversation that i would be refunded and the same thing at the beginning of the conversation i cant get a refund because my superpad already shipped. I spoke with the USPS they have no knowledge of the tracking numder to be in their care ever. USPS informed me that along with my item there were over 500 items along with that. Sears advertised these products on their website therfore they should be accountable for 100% refund. You cant get through to eleectronicdealz.com and sears.com  is trying to postpone this because they cannot either and it is not fair to there customers.