What you're mentioning here seems to indicate that someone else gained access to the account at some point in the past. A ban at that point would be intended to prevent them from continuing to have access to the account while you were not aware.
I'm not showing any cases created from this account yet, so please be sure you've followed these steps to get an appeal sent up to our Terms of Service team. The ban history section on the account does not show all account actions, but you'll be able to create an appeal with the steps in that link regardless. They should be able to get this cleared up for you.