Reporting out of spite, taunting, and intentionally losing games

I made a thread earlier today about the mute feature. The mute wasn't the reason as to why I created it because I'm unbothered, however, I met the player yet again today and found their attitude still shocking.

For context: I "flamed" yesterday in response to the enemy; the Tristana (player in question) remained quiet, and his or her 4 friends did too, up until they broke down the game and were about to close out-- at which point they agreed to surrender. I am not contesting the mute, however, having it removed after this would be nice. Punishment of this player and their friends is what I am looking for here.

Not only have they intentionally lost a game-- using /ff as a tool to lose just as they are about to win, being in a 4-man premade, having 1 random person lose out for no other reason but their "haha we won but we lost funny" joke. I'm pretty sure they've broken a rule there, but:

Placed with this horrible person yet again, they send this message in /all chat. <removed by moderation> Transcribed: "What did your feedback report say yesterday Teemo?" and "Oh, that's right you can't use all chat"

Now I thought that reporting players would block you from playing with/against someone again. The player clearly didn't report me to make the game a better place, they're a bad person too; they did it, simply, out of spite for me-- much like their surrender vote.

Proof that they're premade: <removed by moderation>

Now I know that this community is warming up for some sick metal gymnastics, but the single point this thread serves to prove is that: These players, who abuse the report system to later brag and taunt their victims and intentionally lose games should be punished, as was I.

Thanks.