They insta perma ban you if you basically talk ever again after a 14 day suspension. Riot is the only company I have ever known to permantely remove your account for being a "big meanie". I recommend you just permamute your chat.
I am speaking from experience btw, I had what I felt was an unjust 10 day chat restrict, went off the deep end because I was trying really hard to earn my honor back up and be a good teammate. I got super tilted and went into the next game and said the "N" word 3 times to get 14 day restricted. After my 14 day restriction I made one mistake in a game when instigated on, or instigated idk doesn't matter and lost my account of 8 years. Even though before a month ago I was only ever punished once. 10 day restriction and I did deserve it.