why do i only encounter trolls in ranked?

ive been playing norm games (mf support) surprisingly works well and havent seen anyone moan about it. but i decided to go back to ranked and honestly im just playing norms again. first game i had a darius who hard fed jax and somehow is in silver when he feeds literally every game he plays lol but thats fine, hes getting placed into the rank he deserves.. now the anivia i just had took smite and spelltheif, maxed w first and followed our mid zed around all game long leaving top open..???? he would make walls between us and the enemy trying to get us killed also would use wall on us to interrupt our back animations. tried sending a malicious link in lobby to try to get our ips. like how is this guy not permaed?