Ranking system is impossible

So i go into a game one person rage quit and disconnect because my sunfire cape killed the cannon creep while i was ganking for him--- minutes later he connected again while we are winning the game and decided to surrender guess what there is his premade and the third randomer who feed and troll decided to accept the vote - i lost my ranks because others orders ( we want to surrender ) but i don't want to ? we are winning even if they all afked and i back door we will win but nope they want to make me lose my lp because they can and i have no rights to protest.

the second issue is when my whole team have a 44% win rate and we matched up with enemy team with a winning streak of 8 games and every single one of them have a 60% win rate or so the matchmaking is bugged or something? we already have the artificial difficulty of the children player base + silver elo