WHY?????

RIOT I have one question; why every single game I have 1 or 2 feeding loser in my team and why I have to stuck in bronze bc of them? every victory gives me 17-18 points and every defeat takes 20-21 how am I gonna be able to get higher ranks like this? Also sometimes runes and masteries doesn't work in game; I chose full attack speed runes and my champ still has base attack speed.