Update:
It took some time, but; I got this reply from G2A:
"Greetings,
We are happy to inform you that the complaint process is completed and your claim was accepted. The order will be refunded, you will receive a confirmation email soon. We would like to apologize sincerely for the inconvenience you have experienced.
Kind regards,
Michael D. "
So I think everything will be fine and I won't get saddled with the expenses/lost money (just like is the case with physical shops). I understand GOG (though I feel they should at least have contacted me or let me know something, instead of just removing it without any notice), and I'm sure G2A is not to blame neither, but still: *I* was not to blame neither and buying it in good faith, so it would be weird if only I would get the short end of the stick.
But G2A took its responsibility, so I have no major complaints anymore. It's a pity the game is gone out of my library, but shit happens in life.
