Why Will My Rank Not Move Up?

I was very surprised when I looked on these forums and saw no thread made by someone with a similar problem (on the 1st page).

For about 3-4 days in a row now rotating back between Slayer and Arena, on wins I have not gone up, or seen a green arrow showing there is progress (I have seen reed arrows pointing downwards after wins as well). I won around 6-8 in a row on slayer, my rank never budged, lose 1 and immediately go down.
The feeling of knowing that you’re going in to matchmaking for me the past half week to either stay the same rank regardless of performance (when win), or almost immediately go down (loss) is very discouraging and makes me not want to play on top of the issue of VERY sloppy servers by microsoft. Now that the servers have started to pick up though, I foolishly thought this error might fix itself and be plopped under ‘server issues’, it however was not.

Many online friends have had very similar situations happen to them. Why is this not being addressed and why is there no one else talking about this?