International versions of these phones can be problematic. I would doubt BestBuy themselves sold this phone. I agree that it was probably a seller using the BestBuy site. Much like Walmart does too. And the other giant online places that take money from vendors to sell their wares but not actually selling it directly themselves.
How are you making out with the dial code? I would tend to doubt it has volte enabled. There's another place to look if you can't dial that code.
