So upon analysis, I came to know that your performance in ranked matches was not as good as it should be… I am specifically talking about KDA.
You are playing Core hero mostly and getting only single figure kills and very low assists as well. If you want to move to next bracket, you must perform good. For example, You were Anti mage, match lasted for almost 66 minutes. You had all the possible items, but still your kills were very low and same was assists. Your deaths were also very high in that match.
I wont agree, once you say that you performed well. Because you did not. Try those heroes which give you high KDA, like Anti-mage (with less deaths), Slark, Undying, Axe, Zeus etc…