A Banned from the server after a Free Win of Rank BO3

I just ran up to my Series of my rank, and it showed I got a free win in my promote series. However, right after I joined the party and entered the champions select, the timer counted to zero on the summoner of enemy's team. The screen popped up a window that, I was the one failed in champions selection, then of course I got a lose on my series for no reason technically.

Game was at 1:37-1:40 PM @CA,US

Please help me to fix this, because we all know rank is not easy for everyone.

Appreciated