HereForTheBeer: Note that Support doesn't remove games just because they feel like it - which is why I questioned that detail. And it has nothing to do with your rep or anything like that from the forum. If they got removed, it's likely because those were not valid codes in the first place.

Lately, a number of games have been pulled from customer libraries because the codes have been purchased from sites that resell codes. A number of these codes are acquired using stolen credit card numbers - or at least that's the word we're getting - and then gOg yanks the games once it's determined the purchase is fraudulent.

If your game(s) got yanked then it's likely the gifter acquired them from one of these third-party sites and that the code was originally purchased with a stolen card and then sold to the third-party reseller. In that case, I wouldn't go out of my way to repay the gifter.