Toxic higher elo player in low elo game

I got into a chill game with friends and the first second of the game the enemy Fiora types "Bunch of Bronze and Silvers easy game." We were all confused so we checked Lol Nexus and the person was Platinum 5. He kills me early in the game because my vital was pointing directly at him giving him the perfect opportunity to kill me. Right after he kills me he says "Idiot." Later on he tower dives me when I am low, I outplay and kill them. They say "Wow I'm just fooling around, how bad can you be you almost died." Every time they kill me they flame me. When they die to me they say that they are just fooling around and that they are not actually trying. Later on in the game the Fiora gets 10 times more toxic. They start to brag about how much better they are compared to everybody else (even though their silver Vi was carrying their team). The Fiora gets so toxic and annoying that her own team members are annoyed. In the end I reported them and I don't think they are going to get punished which is the bad part. It's sad how these people are allowed to do this and not get punished for doing so. I would be fine if somebody of my rank would be calling me trash, but a higher ranked player going into our rank and calling us trash is disgusting.

tl;dr Toxic Plat 5 Fiora flame us bronze and silvers. Reported. I don't think they were punished. Sad life. Really Rito?

If you want to take a peek, here is the game. http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2071303471/216573349?tab=overview