Wow, that's actually ridiculous. You should get a refund, but knowing how much activision loves their money I doubt you'll get one.
I was just in a game with 3 guys teaming. And it clearly shows them land with a helicopter together loot around me and then not shoot each other but come after me. I killed one then the other two killed me then got in separate helicopters and went to the next zombie location together then was in the boxing ring together and didn't kill each other. It's a shame man.