I have the same problem and it's a complete surprise to me. I called EA today and they keep telling me, that only solution is to refund and then buy from Gamestop etc. So they're saying me, that if I'd like to experience game in it's original form then I need to buy outside my country...
Great.
Which is so wrong... why to keep people away from experiencing original version of the game?!...
It was an unwise and unjust decision from EA to make Polish and Russian only available languages for CIS-Poland region. The only option as the customer support said is to buy from a third-party site. Changing the game files is not recommended, though technically possible (requires files from the ROW version).
Just in case, there was (still is) a warning on the store page about supported languages and has been this way for a year or so. Unless many customers will disagree openly with the language lock, nothing changes.
So far, it look that the only way to ask EA to unlock this. There is petition going. Chip in! https://www.change.org/p/ea-games-titanfall-2-remove-regional-lock-for-pl-ru
