-snip-
Banning all my accounts is totally unfair for me, I didn't used my alt accounts for any that can cause banned like spamming or plagiarism, I made a mistake for once and why all of my accounts should suffer like this?
That's because you broke the rules and got banned. Again,
YOU; and not only that specific account. If all those accounts are owned by you, and you can't use the forum anymore (whether it be with the one who posted the plagiarism or not), there are no reasons to keep them unlocked.