The only time I feel the rage rising is when someone plays horribly and then starts blaming other people.
(As in "bot stop feeding", after instalocking mid, and while I'm 1/2/0 and he's 0/5/0, and my only two deaths where due to his mid freely roaming and towerdiving)
And even then, my suggestion is: realize that you are speaking with an human being and not to a computer. That guy on the other side has feelings. And is probably an idiotic 12 years old who thinks he owns the world.
Would you scream in the face of a 12 years old? I wouldn't. I'd pat him on the head and say "there there", and that's it.
Try it next time. If he's an adult he will realize his mistakes on his own. If he's a kid well, he's a kid. No amount of screaming will change him or make him play better.