I understand that its hard to know all or most of the products in a store like Walmart, Target, etc. But really, one look at the box art on that and the person should have known it wasn't correct. Most stores I've returned to have at least checked to make sure the right item was in the box. Otherwise, you could buy something expensive, like an iPod, take it out, leave something random in the box, and return it. They just don't really care about toys, though, in my opinion. I mean, they don't have any security on them, either. You could literally just take a box out and no one would notice.
Sadly in this day and age, the customer is always right (even if they are a cheat). Im so glad that I don't work in retail anymore. The stories I could tell you.