Explanation for ban

Chat logs:

Game 1 The lsland: brand you got the right runes? The lsland: why The lsland: i was joking bud The lsland: what an awful attitude The lsland: he asks me in champ select if i like playing aggressive and i said no i like to stay back and miss cs The lsland: thinking hed know it was a joke The lsland: and instead he gets all butthurt lol The lsland: cmon man The lsland: you wouldnt like if this was done to you The lsland: ITS SUB 30 NORMALS BUD JUST PLAY FOR FUN The lsland: i dont understand why youre doing this The lsland: so mean for no reason The lsland: im being trolled The lsland: no reason to play The lsland: sub 30 normal game The lsland: it means i am not level 30 The lsland: i was trying to play The lsland: and brand would sit under tower The lsland: i cant play The lsland: i tried to talk it out with brand The lsland: i know youre probably just queued with him The lsland: but since he wont be reasonable, you can go fuck yourself The lsland: nah, im fed up The lsland: no reason to tolerate dickheads The lsland: nah The lsland: i already told you it was a joke The lsland: if you wanna be a fuckhead about a joke, thats on you brand The lsland: go fuck yourself The lsland: quit defending a dickwad just because hes your duo partner The lsland: what, youre mad that your little trolling got turned back on you? The lsland: awwwwww poor brand The lsland: i asked brand to grow the fuck up and help me instead of afking under tower The lsland: and just got static The lsland: and now his duo partner and him are mad theyre losing The lsland: so pathetic lol The lsland: i make a joke in champ select and brand goes full retard The lsland: thats true tilt The lsland: lol aftershock brand calling me a troll The lsland: i realyl couldnt care. youve shown me how terrible this game is The lsland: yea do it The lsland: go ahead and email the chatlogs, the real story will come out :)

Can anyone explain to me why this was a first time permaban? For context, during champ select, our support asked me if I liked to play aggressive. I said no, I like to sit back and miss cs, assuming that he would take it as a joke. He locked in brand and said nothing. In the game I asked him why he had aftershock, and he said he didn't need the right runes because he was going to sit under tower anyway. This happened the entire game, whenever I tried to move up into lane. I played for about 12-13 minutes and then went to do other things on my computer. Game was unbearable. Then, him and his (I assume duo partner) start gaslighting me, asking me why I went afk and telling me to stop trolling, so I leave the base and brand immediately goes back to sit under tower. At this point I pretty much just quit. I a) don't see how this is a first time permaban, and b) don't see how these players deserve to remain in the community when they do awful things to people who are just trying to joke around. If someone could tell me how to attach a replay of the game to see what went on, that would be appreciated.