What do I do if two people from my giveaway wont accept the gift?

Add them on steam. And always set a bit CV on your giveaways, just in case.

Here are some things you can do:

1) Add the person on Steam and chat with them directly. This may work.
2) Wait for seven days and then contact Support for a re-roll. Include screenshots as evidence. This works, but slowly.
3) Send an email to the person's email address. Say something like, "I'm sorry you don't want your game." This works quite well.

Pit them in mortal combat with each other!

The winner will receive the gift they didn't claim. The loser will also receive the gift they didn't claim.

Give them to me. Just kidding, obviously. I think you have to wait up to a week, if that elapses talk to support.

As stated, wait a week and then ask for a reroll of the ones not yet accepted.

Or, I'll take one as I was one of the entering losers of it. :P

Having the same issue. Made my first 3 giveaways. The 3 winners were active right up until the contest ended then they have not logged in here or on steam. One was a humble link so wanted to make sure I do it right but I don't know if I want to do giveaways if I have to spend days chasing these guys down to get them their codes.