Thanks for the reply. I have checked my box 5 times. Took out all cards and double checked each divider also. No banished cards divider. Hopefully they will send a replacement soon. And that it comes faster then the game shipped.
The Banish card divider is really only cosmetic, so don't let that delay you from playing, or enjoying, the game! You can just chuck the banished cards inside the box cover for a more thematic solution in the meantime! Have fun.