Just here to rant about ranked and its matchmaking

Just here to rant for a bit, I just plain dont understand the matchmaking system. Got to mid plat(3) 2 seasons ago, didnt play much the next season stayed in gold, now im forever stuck in gold 5. I get 9-13 points a win and 24 a loss. I dont know what to do and I finally snapped just this last game 5 minutes ago. We won bot lane incredibly hard, our top didnt do bad and our jungler didnt feed. I was happy...we were winning by +10 kills. Then our only person not doing well on our team...ahri. Im not going to rage about how god awful she was..im just going to point out facts.

She is on her 4th placement match...4th FUCKING placement match...she has lost every single placement match thus far. To make it even WORSE those are her first 4 games since june 2015...where she was low silver. I mean fucking really riot? I was on a 4 game win streak finally stacking my LP off of winning then losing etc etc. Regardless of my w/l hidden mmr whatever the fuck riot claims to use...how is a silver 5 from more than a year ago while in placements paired with me? She completely threw the game because "annie is so fucking broken she does way too much burst"...Blindly following the order of recommended items and not understanding mechanics or the champion at all. Really? Like wtf did I do to you riot?

TLDR

Got paired with an ahri who: Hasnt played in over a year was in silver 5 when she did play is in her 4th placement match has lost every single placement Didnt even understand the basics of the game

ty for reading sorry just need to rant while I go back to WoWs new expansion.