Please explain to me....

I have been playing this game for going on 3 years. I dont fancy myself a good player, but im not terrible either. I main jungle and often do fairly well with Xin Zhoa and Vi. I enjoy this game, Ive made lots of friends on this game, and a lot of my time is spent on this game. BUT, please explain to me how this works. I recently completed my PROMOS for ranked. I did ok, going 5-5. A friend of mine had the same outcome and was placed in Silver 4. Yet somehow, I got BRONZE 5!!???!!?? I am furious!! I carried all of the games I won, going 16-6-10 in one of my more recent ones. After playing YOUR game for almost 3 years, I have yet to make it out of Bronze, even though I carry most of my games when I get my best role. I know its just a game and people are gonna tell me to chill, but I cant right now. I need to understand HOW and WHY this happened. So please, explain to me how this is fair! I am on the verge of uninstalling the game because thats how upset I am. RIOT, EXPLAIN THIS TO ME!!!!!! Sincerely, The Blue Wookie~~