Why can french players insult you in french and not be banned about it?

So how can a french player insult you in french and not get banned? but if you for some reason insult the same player in english you get banned? (i didnt get banned, nor chat restricted i just wanna know this because in the past few week i've been seeing this type of behaviour not getting any type of punishment ) i've tried also to contact rioters and ask about this but they simply ignore this and sometimes ban these posts for "Racism" while im just exposing a in game experience.
Report as:
Offensive Spam Harassment Incorrect Board