Got the wrong regions code when I ordered the game

Hello!

I ordered the game (ARR+HW) on amazon, and I had no idea that it has different codes for EU and US... apparently the one I got is a US code... Now I had a f2p account with a level 10 character ...
Now I don't care about the account, since it takes like 30min to get to level 10, but I live in the EU, and I would like to play on EU servers, which I probably can but.. about payments...
Can I pay normally like I would if i would have an EU acc? Using a european credit card through paypal to buy crystals, and then sub with those? (same price, same everything?)
And what about future expansions? I won't be able to order the physical copy form the US to the EU can I? Or even if I can, transport fees... since I guess those will have some code too, and since I will have a US account, I can't order from the EU anymore...
Or generally will I have any disadvantage with a US acc, being from the EU, playing on EU servers?

Or is there any way I could make this code EU? Can square enix upgrade my account, and remove the code manually from the system, or anything like that? Amazon won't refund games, and they didn't mention anything about the codes, and it wasn't specially mentioned anywhere... pretty bad from the companies side.....

Regards.