Well, the message you got reminds me of the message in MW3 MP.
(And that would mean you have been banned or closed out from the multiplayer (Zombies as well))
You have been banned by "Activision" trough their report system, VAC would only blockade you from Multiplayer
Verify game cache. Might be something wrong with playlists. IDK something
Uninstall. Reinstall.
If it doesn't work.
You got banned.