you are making the same point EVERY banned person tries to make when they rage at being banned.
"You should tell me why I was banned"
You KNOW why you were banned. You probably know the number of times you've afk'd, or left the game, or been vulgar to your team, or been a ******. We all have bad games, and sometimes take things a little too far. I feel the line between those that get banned and those that don't, is the ones who do feel remorse, guilty, or at least paranoid that their actions will have consequences, while the ones who have become A-list celebrities in the tribunal don't.
If you honestly don't know what you did wrong, then I must blame your parents for a poor upbringing on etiquette and social behaviors.