Why am I banned for 2 weeks?

I was playing a game of league of legends PC: Edition with my friends when they instalocked the champ i was gonna play and stole my role. so i picked urgot

I've been a quite good player and had good behavior. My friends were making fun of me and calling me "%%%%%" seeing as im asian but even so i didnt really care. Later on he raged cause i took 3 cs. he afkd so i had to solo lane against soraka and tristana. i decided to troll in the end and went 6 tears later we lost and so i logged off. When i logged back on i was banned for 2 weeks for my very first ban and after that i went to my email and it said this "This is the only warning this account will receive. Further examples of toxic behavior can result in permanent closure of your account." i don't understand why i barely get any warning. i would have learned if it was 1 day ban and realize what im doing was wrong but instead they skip it all the way to perma??/ i dont think that is quite fair.