If you believe that your ban was inaccurate, you are welcome to PM me to discuss further. However, since you claim your brother went looking for cheats, that seems unlikely.
Cheating bans are permanent and there are no warnings. We take this very seriously in order to ensure that everyone has a fair and fun time playing Fortnite.
Additionally, as stated here, we ban computers associated with banned accounts in order to prevent account churning to bypass our bans.