For a better experience please use the new Ban appeal interface https://ingame.ro/Stats/Appeals/
For Garena players bot will show slots maxim 10/12 and never 12/12. So, if game is full they cant join (but arent banned).
AFK is a valid reason to be banned.
Players from Garena if they are disconnected from rooms (they are players with numbers nicknames instead of curent nickname) they can join in bot. To solve this issue go and restart the Garena client.
If you are banned for MH, don't try to lie. We really can detect in 97% of cases!