If it just says "You are banned from this server", I'm sure that means you were permanently banned. Depending on the level of the rage you vented out towards the admin, the ban may or may not be fair. Bypassing the mute accidentally shouldn't really be a ban longer than a hour or two in my opinion. Asking for admin once shouldn't be a reason to ban, but over and over with repeated "No's" and your risking punishment, but that should be a short ban at the worse. To wrap up, the permanent ban may or may not be fair depending on the level of anger you showed to the admin. Screenshots proving this really happened would also help.