Ranked WTF

At the start of my ranked season in s5 i won 2 of my provisionals and placed in bronze 2, i lowered throughout the season to bronze 4 and near the end was able to raise it up to bronze 3. I spent all of today playing and won 7 of my 10 provisionals. Needless to say, when you win 70% of your ranked placements and get placed in bronze 5 there is clearly something wrong with the ranked system. I know that bronze is already the worst division but when you do exceptionally better than you've ever done before, the game should try and reward you for that, not put you down further than you ever were before.