Is not bannable. You can host your own game or stay in lobby and watch if its setup is what you want. When someone is hosting a game he can pub it with any name he wants. If we start banning for false gns then 99% of owners will get banned; just think how many games get "+1" in their name, as example, and when you entry the lobby it needs at least 3 more.
About mode changing, most of the times when this happens is not a scam. Usually other players ask to change the mode or the owner just changes his mind. The lobby is for waiting, if you had better things to do or just were bored waiting there and go on Fb then its not owners fault.
I guess you played in an "ap" but "ar" earlier. If yes, then I was crix. I wanted to play invo, that's why I joined ap and the host modified the mode into ar. I stayed on Fb, while waiting the game to start, so I didnt comlained about mode changing.
EDIT: do you know what is bannable instead? cursing several players via whisp. I see now that you were demonized. You whispered flames and curses to each one from the opponent team, including myself.