Deleted

My account has never been limited after they have removed beta this way. Its more likely that your account is limited if you would have been able to remove this game yourself. (And thats not likely either because its not a game you have bought.)

If neither approach works (I've personally never had a beta key I couldn't deactivate through support, so this is new territory), the only thing I can figure is that it counted as an opt-in. Right click on the game in your library, tab over to 'Betas' on the far right end, and see if you can opt out.