First question: You banned me during a game and its marked as a "Leave" is that an other Leaver Buster thing?

Second question: How do i find out at what hour have i been banned?

Thank You.

Leaverbuster deals with punishments for leaving. But if you were toxic in other ways during that game it's still valid to report it to the Tribunal as well.

Normally the time you received the email about the ban reflects the ban time pretty accurately. Though there have been some issues with these emails in the last week while Riot's adding new features to the Tribunal, so I can't guarantee that will be real helpful (but at worst you'd be unbanned before the email time implies, not after).

I never received an e-mail...

just try to login, it will tell why you were banned (tribunal, leaver buster or riot staff) and when it will finish.

It docent show at what hour it will finish.