I just encountered a pretty serious bug. It seems like the website allows you to accidentally buy games for yourself that you already own. Before the recent site update, the system would prevent you from doing that.
Here's what happened: I tried to buy a game for someone else, but I forgot to active the checkbox to indicate the order was a gift. However, I already owned the game in question. So my order went through and my payment was processed, but I didn't receive a gift code because I hadn't marked the order as a gift.
Since I had already owned the game before I placed the order, I literally received nothing for my payment.
I think that you ought to contact GOG support , they will probably help fixing things for you.....