Need advice

I really want the game too.

Edit: gave him/her permission to delete giveaway so he/she doesn't feel bitter towards me.

You have 2 options now:

• Accept the deletion and move on
• Refuse the deletion and mark it as not received

Either way, doubt you will get the game so it's more how you feel about it and if you care enough to mark it, just make sure you don't mark it as received!!

The only options that are in your control are allow them to delete or mark as not received. Both result in you not getting the game unfortunately.

I've gotten a key from Humble where it took 5+ days to get a response and slightly longer to get a new key from them. Winner said it was okay to delete since these types of things happen, but Humble was able to provide me a new key (just took 3 weeks) Also depends how long ago it was bought for Humble to not reject a ticket (in some cases, this is a luck of the draw on the representative you get). While grey market is a possibility, I wouldn't immediately jump to that conclusion.

That happens, even with not-grey-market-keys. In fact, the 5-days wait and the rejected request look a lot like Humble and the way they handle things. They probably sold the key to someone else since it was not activated. Sometimes they give another key, sometimes not, even with proofs. They just say the key is too old blah blah...
That sucks if you really want the game but look at the bright side : you didn't lose anything.
So two ways to end this :
mark the key as not received, which is your right and the "official" way (but can be considered by some as rude),
accept the deletion of the giveaway, since the GA creator was open to communication and spend some time trying to find a solution (not everybody does that)

That happens. Now you have two options:
1 - Be kind, agree to let the giveaway be deleted, and you both move on with your lives.
2 - Mark it as Not Received just to leave a mark on the host's profile.
The choice is entirely yours, but keep in mind that at any point, a key you create a giveaway for could have issues too.

Your only real options are to agree to delete or to mark the gift as not received after 7 days.

I’ve had several games I won on this site that I couldn’t activate, and only once did the sender go out of their way to buy me a replacement key. It’s disappointing, but when a key doesn’t work, I chalk it up as a loss and move on. Each time, I agreed to delete, because I’d hope other people on this site would extend me the same courtesy in the handful of cases where I’ve been in their position. Nobody wants to give or receive a dud key, but it happens, so it’s best to just move on.