4-man team intentionally feeding.

We started off in champ select with me calling jungle, choosing my jungler, waiting a few moments to make sure I got the jungle call, then locked in. One of the team members asks me if I can go mid because they are a 4-man que. I said no, Kayn isn't a very good mid laner against many match-ups. They say, quote; "if you don't go mid, we will int, all of us, we are a 4 man team and we will int."

Not wanting to be intimidated by their scare tactics, I said; "if you do, I'll just report you all."

They said "go ahead" and the match started.

Whewwwww what a match. It started with them all running down mid and dying almost immediately. Then, they followed me to my red buff and tried to steal it from me. After they failed to do that, they followed me around the entire jungle stealing my camps. After I began defending mid from the enemy team 5-man siege, who knew my team was inting, they would constantly run into the team, teleport onto wards/minions knowing they'd die, etc. It wasn't until around 10 minutes in that they began "trying" to kill the enemy team. As the fight progressed, although they knew we were way too far behind to win, they continued "trying" to win, and acted innocent when they were called out for inting.

I have video recordings and screenshots of pre-game chat of them all saying they will int if I don't go mid, and then saying that they will int. My question is; how do I make absolutely sure that these recordings and screenshots find their way to the proper authorities?