Hi. Before I hand over the key to a winner I check their steam account to make sure the game is not already owned and use sgtools to check for any unactivated wins or multiple wins. Sgtools flagged an unactivated win and some old multiple wins. I sent in a support ticket for them to check on the unactivated win.
Once support has cleared that I will release the key.

Yes, the system is not perfect and because there are millions using steamgifts, but only a small number of support staff, things take a while.

The game that flagged sgtools as unactivated is a fairly recent win of yours - Yet Another Zombie Defense Hd. This game was won in January of this year. Did you maybe forget to activate it? Might be worth checking the key again. If that is all it is, when you activate the game I can check sgtools and cancel the support ticket to give you the game.

Otherwise I wait for support. They currently take about 3 days, although they can take longer.
Usually support suggest that if things are held up, the winner should tick not received at the 7 day mark. When the key is finally released this can be changed to received.

Yes, it looks like you activated that won game. My problem is that if I put your name into sgtools ( https://www.sgtools.info/activation ) that game shows as not activated on your account. I also cannot see the game in your steam library. So maybe support will be smarter than me and find out where I went wrong.

You do own Yet Another Zombie Defense, but your recent won game, Yet Another Zombie Defense HD, does not show up.

Yes, this is an issue that becomes more common :(
I added a statement to my ticket that included what you have told me and also the link you sent me detailing your won key for the game. Hopefully support will be able to tell the key is not correct and delete the giveaway, which means this problem goes away for us (and you can get your game). We just need to wait for a bit.
As I may have said - if support take longer than the 7 days, you can tick not received on my giveaway. If you do get the key then you can change this to received.

I have Yet Another Zombie Defense on my steam account too. I decided to give your won key a try. It came up with the message that I already owned the game that the key related too. So ... now I know that the giver did not give you a key for Yet Another Zombie Defense HD , for sure. I have decided to delete my support ticket and send you the key. I would suggest you continue with your support ticket, to hopefully get that giveaway deleted. Even though you deleted your YAZD game on your steam account, activating a new key for the same game does not use that key. I think you have to go through support to get them to delete the licence. The key you won ...may ... still work for someone. But I would not gift it on steamgifts, it may not work. After support look at your ticket you could ask a friend who wants that game to try it. Good luck.

Good luck and enjoy the game :)