GoldOmega, afaik our night shift support team emailed you about 1 hour ago... We do not question that your friend bought the game - the real question is really whether your friend bought it on GOG.com website or bought it somewhere else (and if so... where?)

All in all, the original purchase of this key was done few months ago was indeed done fraudulently and hence the issue - please do get back to us via mail, we'd love to learn more and help you as much as we can.