Instant 14-day ban for defending myself?

Hey I am normally never toxic, I definitely never start flaming. However I had a game where my team was flaming me very hard on an already frustrating day. So I responded to my flaming bot lane: '%%%' as in '%%%% off'. Then muted them. 10min later top lane joins the flaming party so I give him the same response and mute him aswell. Then we lose the game, probably got 3 reports because they were typing stuff like: 'report veigar for feed' etc. Then get pulled out of champ select 3 min after my game finished to instantly get a 14-day ban thrown in my face. I was defending myself here against very mean people and I don't have any history of punishments or other toxicity. %%% is such a common word on the internet, and using it twice in a defensive way in ONE game results in instantly getting banned? I don't think this is fair at all, riot should only ban consistent toxic players, especially the people that start flaming/trolling. I find this very unfair, and the lack of customer support and explanations are even worse.
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