At walmart I asked if the white 16 gb iPad 2 was in stock. They said no. I saw a box behind the counter that had a picture of a black iPad on it. It said 32 gb and it was $499 so I said why not. When I returned home I looked on the back of the box and saw a copyright date of 2010 on it... So it was an iPad 1.

Upon opening the box I found a white 16gb iPad 2 inside. One of the employees must have hidden it there. Obviously I want to return it because I can get it cheaper elsewhere. How do I prove it to wal-mart?

You don't need to prove anything...just return it...I believe Walmart has a 30 day return policy (maybe a bit less for electronics...?)..

No it didn't. I never really got to hold it while I was in the store. I assumed all boxes were new. The cashier took out from behind the counter and bagged it after I paid for it. When I got home to open it, the box was already open.