You have to understand what a [compromised account (CA)] is.
It means a third party accessed your account, you were banned for CA.
Change your password, make sure not to click suspicious sites such as "free capes/ranks" as that's mainly how they get into your account.
This is for safety measure so that your account wouldn't be used to hack/break rules in game.
appeal here:
https://appeals.cubecraft.net
Feel free to PM me if you have any other questions or issues.