I do not understand the ban on my main account,

For an account that was stolen over a year ago, like a smurf account

I have not used it for over a year.

This is my main account:
http://battlelog.battlefield.com/bf4/pl/user/asvel82/

https://bf4db.com/player/827099980

I assume this is your BF4DB profile? Please click the "Claim" button on that page so we can assure you are the actual owner of the battlelog account.

confirmed

I think we have a mix up here. Will set your case to "investigating" till we get this figured out. In the meantime, you should be able to join BF4DB protected servers again.

https://bf4db.com/player/ban/827099980