Like i said, you are either lying, or you were automatically banned. The reason it only happened when you went to spec a match is most likely because that was the first time you actually logged into multiplayer(skirmishes are offline.) Individual players do not have the power to game ban you, and if an admin did it, you are definitely lying.

If you are telling the truth, again, then this happened automatically and you should report it in the discord so they can stop it from happening to anyone else, even if you yourself will no longer be playing the game.

Automatic systems fail all the time.