Both the A3 and A3E, as I see on Vizio's site, go for the same price ($999, with the A3--package with expensive remote--on sale for $899 at the moment). So, in that way, it's not a mistake. And they were (moderately) honest about the difference in models.
Plus, as much as I want to believe store web sites perfectly match up with in-store inventory, I know it's not like that, and the model with the basic remote has probably actually been on sale in some WalMart stores --as well as other stores -- long before now. Ignoring the stores' role, Vizio could have easily had just as much of a role, since manufacturers themselves have been known to alter feature sets for certain destination markets without making it well known.
But since both models exist on Vizio's site, with the difference listed in the tech specs... Eh, it's not totally obvious, so I understand your frustration. All you can do is learn from it and move on! Gotta be careful to go over the fine print with a magnifying glass and get every single question resolved beforehand.