Don't complain about getting banned..
I will get straight to the point: You shouldn't complain about getting banned. I'm a pretty toxic person my self in-game, and it's not uncommon for me to use some strong language such as "wtf is wrong with you" or "pls go uninstall" whenever I am just overly frustrated in a game. Despite all this, I have NEVER been banned due to toxicity in chat or in-game, and I've been the same for the past two seasons now.
If you got banned because of verbal abuse of any sort, then you must've been using some ridiculously strong language. Stuff such as death threats or racial words are definitely reportable, even in real life, so you know that there's a pretty good chance that you'll be reported after using them. You really shouldn't lie to yourself and other people by saying "I flamed an inter and I got banned how is this fair" blah blah blah because that's complete bs.
We can complain about the Ban system all you want, but nothing will change unless you keep the strong language to yourself. Period. If you see someone inting go and wait to the end of the game and report them. You know flaming them will never benefit yourself.