How is it possible to do 7 times the"7 wins" AndBeStillB2?

I am a player who started ow1 from 2016 and in 2018 I arrived diamond playing dps and tanks, making my return in this I cannot explain how it is possible that after having made the “7 wins or 20 defeats” for 7 times I is still b2, precise, I started s3 with the placings, after the first 7 victories I dropped to b2 and from there I did 7 times the “7 wins or 20 defeats”, you can solve this thing is very annoying.
I do not think I deserve the B2 when you see that it is not my elo, always doing king dmg or almost and always finishing in the best actions of the game…
pls fix that is not funny for the competitive player!!!