Flaming, hard flaming

So i just played a normal game with twisted fate testing out a skin i got from a mistery gift a while back. Havent played him in a while and i didnt do so well. And we lost the game, throughout the entire game a caitlyn from my team has REALLY gone to far, stuff like wishing me and my family cancer, calling me an idiot,retard and a noob, he was saying he "f***ed my dead mother" and stuff like that, as he only flamed me and just a little bit the enemy team, im suspecting im the only one reporting and it seems like this guy wont get punished cause its only 1 person reporting. I have multiple screenshots and i can send them to riot but i just didnt find anything of this kind on the riot support. What should i do, cause this guy just made me really angry and upset.