Keep getting matched up with max diamond...

So i am unrakned. Ive never been bronze or silver or gold ive played like 6 ranked games last season. But for some reason im getting matched up with silver gold plat and even diamond!? What is going on?? Okay diamond is rare but i usualy have a team like silver gold gold unranked plat. Or something like that. And getting premade all the time? I dont think so..Is the matching system broken or are everyone in league best friends? Please tell me its not like in Smite.