Bronze and silver elo

Ok so i just played a ranked game and in this game i was actually winning my lane as a sivir against twitch and sona, but as usual in this low elo people just decide to go afk or just troll. I was 3 and 0 at less than 10 mins and had like double the cs and top was owning as gnar against jax, but 15 mins in my mid decided to go afk and leave the game and so did my jgl after 3 mins, and the enemy team wasnt even close of winning the game before they went afk. I beg to riot to just ban these people from the game its really annoying and it kills every little bit of fun i have playing this game...