Plutonium

Please anyone reply , what do i do now ???

But it's my account and i didn't cheat , what do i do in this situation ?

Today i went to my friends house for the last time , he was going to travel to England with his family to live there , well he decided to give me his computer ( an old laptop ) as a good bye gift , well i found out he had BO2 installed so i made a plutonium account and decided to play a little . When i logged in everything was normal until i get a message telling me that i was banned for 36000 Days i think ?
Note : he was next to me and told it might be a glitch and i should contact the support team , then i asked him if he tried to cheat once he told me he did and it might a IP-Ban or something .