Same thing happened to me. I found a cheaper on at Academy during a sale, so I wanted to return it. But the box was open. They told me i couldnt return it, even though I had a receipt. So I told her fine I would exchange it for another one, even though I didnt want another one, I just figured maybe I could get a closed one and sell it on craigslist. While I was in the store I used my phone to look up the policy online. I realized I didnt need my receipt to exchange, so when I went back I told the CSR. that i magically couldnt find the receipt. So I got the same exact air mattress, just a closed one. then took the new mattress with my receipt that i magically found, and returned it to a different walmart the money was credited back on my card even after 35 days.