Competitive Deathmatch Rank System

@PlayOverwatch is there an calibration issue with competitive deathmatch ranks?

I recorded 55 of my 60 games and placed diamond 4.

I was:
1st - 31 (56%)
2nd - 16 (29%)
3rd - 7 (13%)
4th - 1 (2%)
5th-8th - 0 (0%)

I am still diamond 4 without technically losing a game, especially for as many games as this. I’ve played most of my time as Wrecking Ball, but noticing the stagnation, I tried Reaper (3 firsts, 1 second, 1 third) to no avail.
I DMed one of the players, who I beat two of the three times when we were in the same lobby and the player was diamond 1. May I please get some explanation or feedback from other players who felt the same way?