For those who wonder why WotC would hold a store responsible if someone they sell to is moving cases overseas, here's a scenario..
1) Large internet store (doesn't matter who) cannot ship boxes out of country
2) Large internet store could make a great deal of extra profit if they COULD, because they could easily undercut the folks buying from the 'correct' distributors for those countries.
3) Someone approaches them saying 'sell me boxes at cost, I'll ship to 'X' country and we'll split the extra profits'. They agree and sell this guy a ton of product and make nice extra money.
4) Stores in 'X' country start hearing about a flood of product coming in from overseas whose prices they can't touch and eventually they start complaining up the chain.
5) WotC starts digging, finds out who they shipped it to in the first place and starts going back down the chain. They know the last place they can point to and say 'we know it was here' was the Large internet store above.
We all know that people might in ones and twos do stuff like this, but I'm guessing (total speculation) we're talking about a LOT of them. Of course, I have no idea at all if this is what happened here, but the possibility of this is why WotC has the rules they have. For the concept of regional distribution to mean anything, they have to have some way to enforce it...
As for the BBB..good luck on that one...
