They have either run out of keys or authentication servers are offline, any new players with new keys are not going to be able to play the game. Buying from a different site will not help because they all activate on Steam.
I contacted Activision support and they told me to contact Steam support. Steam support told me to contact Activision support, even after explaining that I already did.

TL;DR - Don't buy for online, you can't make an online profile. No fixes work.

They have either run out of keys or authentication servers are offline, any new players with new keys are not going to be able to play the game. Buying from a different site will not help because they all activate on Steam. I contacted Activision support and they told me to contact Steam support. Steam support told me to contact Activision support, even after explaining that I already did. TL;DR - Don't buy for online, you can't make an online profile. No fixes work.