Ranked system is broken?

So as many of you have probably know that im another bronze scrub who complains about the ranking system because im bad, well, no. This time its not the case. In fact i think the lol ranking system is a bit screwed up. btw this is written on the second day of season 7, The issue im having with this ranked system is inconsistency in what enemies im facing and the end result (rank)being completely bs. Ive played all 10 placements. won 8/10, and got placed in bronze 4. Thats not the end of it. Ik ur rank is based on who ur up against, but after winning 6 games in a row(hard carrying except for 2), i still ended up facing a bunch of unranked/bronze players in the final match, which i carried again. I did play yi a lot(very fun to get pentas, even though 4 of them were stolen)not sure if playing the same champion will lower ur rank or somehing, but still, i think the ranking system is either broken or bs.

Rito plz fix this thank you.

Edit: Finished my flex, won 4/10 games, and still got b4. I literally won twice as may games and got the same rank. Rito plz fix