It is standard practice to never tell people specifics of what they are being banned for. There is multiple reasons for this - to avoid possible retaliation against the player that reported you, avoiding giving information that they might use to improve any bot/hack they might have been using, or in general telling players what we look for so they learn how to game the system by trial and error and collecting what GMs say. That's why you'll almost always get cookie cutter responses back no matter which live service game you're on.

I guarantee you the GMs don't enjoy banning people for shits and giggles. If they reviewed your account and sent you back an auto response, then they had good reason to uphold the ban.

Source: Was a GM in another big game.