Steam said the cd-key cannot activate the game for my region. I bought the game in my capital city. Don think i've seen anyone with this problem.
You are simply not giving enough information concerning your problem. Try telling us where you are now located, and where you bought the game.
Aside from that,
Some steam games (Game Versions) are region locked. Moving from one place to another or trying to activate a region specific game in another region may not work.
You may want to consider contacting steam support on this issue or returning the game for a refund.