EDIT: Looks like we all got the full game instead of Binding of Kin. @Cartire said that they'll sort it out on Monday as they have a record of who redeemed it!
EDIT (10/25/21): AW Arena emailed another code to the people affected by the Binding of Kin key mixup but a lot of them are duplicate keys as far as I'm aware. This seems to be a publisher issue not an AW Arena issue, but the admin Cartire said that they're going to get back in touch with the publisher and try and sort all of this out.
This is pretty frustrating for everyone but hopefully it will all be sorted out soon!
EDIT (10/26/21): They replaced the keys again and they're working now. Go to My Account>My Giveaway Keys to see your new working code! Thanks for sorting this all out Cartire :D