Players who tell you to kill yourself post game

I just hate the people who get so salty post game, that they tell you to kill yourself. I just had a guy who was super toxic towards his adc (skype call yelling at me about his adc) and he then abused me after game, calling me trash. Sure, I fired back at him, because I was salty about losing. But he then tells me to kill myself, because his full ap Blitzcrank did more damage than AD Fizz top lane. I bought more wards, took more towers, secured more dragons, and was not as toxic/rude toxic in chat, but he was. The people who tell other players to kill themselves should be permabanned and blocked by their IP address, because that is just not respectful. Sure, I get toxic and rant about stuff in game, but I add the person I was toxic to after the game and apologize. I try my best to apologize to my team if I get salty, but the killing yourself thing is the most disgusting thing I've ever seen. I'm tired of it appearing in game, post game, and in champ select. Can Riot do something about this?