I recieved a 2 week ban for abusive chat, however this was my first reported case

Me and my friend often talk stupidly to eachother in game. At the beggining of the game we said some stupid things (at eachother, not aimed at anyone else) and the rest of the game was 'gj's and finishing with a gg wp. At no point was i directly toxic to an individual i didnt know. And shortly after the game ends, I am greeted with a 15 day suspension. I have never been chat restricted in 4 years of playing, and on my first offence its an instant 15 day ban? I would happily accept a chat restriction seeming that i never troll any games and rarely flame, yet on my first offence I am 1 step away from a perma ban. How is this fair? I have had two support members review this and both of them dont explain why it was a 15 day ban, not a chat restriction. Neither of them as well tell me how what I said was ban worthy, and what I said to get banned. I honostly feel that the people who reported me just didnt like me as I wasnt playing well that game, if I said something they did not like at the very start of the game, maybe I should of been told by them or the support team, so I know not to joke with my friend anymore. Does saying a couple of silly things to a friend at the start the game need to result in a 15 day ban as my first notified offence?