Weird glitch.

Reroll happened.

Solved.

kk what does a reroll do?

Could you provide a link to the GA if it wasn't private?

if it was a re-roll:
The giveaway creator created a support ticket, and asked a mod to select a different winner from the pool of entrants.

A mod will only grant a re-roll request under specific conditions, such as (but not limited to):
Did Not Meet Requirements (if the giveaway had approved special rules)
Did Not Own Base Game for DLC
Leaked Giveaway
Majority of Bundle Exists in Their Account
No Longer a Group Member
Previously Won the Game, or Already on Account
Regifted or Did Not Activate Previous Wins This Month
Suspended or Inappropriate Behavior
Unable to Contact Through Steam or E-mail
Winner Rejected Gift

I dont even know what I "won" it probably ended while I was asleep/