What in the actual fuck is this ban system?
I got a 7 day competitive ban because I crashed for about 6 rounds of an unrated game with friends(I haven't gotten any AFK penalties for 4 months), like who makes this stuff up?
If you had a history of consistently dc-ing in games, it carries over. I think they do wipe the slate clean, although it depends on how egregious your dc-ing used to be.
Riot is horribly incompetent in terms of bans. around september last year, i received a perma ban for "cheating". took 1 month of arguing for them to realize i didnt cheat, so i finally got unbanned but they are really not very smart