Promotion Series Miscount [CLIENT]

This has never happened to me and I have no clue what might have caused the bug or how to reproduce it.

However, I was just into a promotion series for silver II and after playing the second game of the series (I had 1 win and 1 loss) the client announced that I have failed my series. Even though I was pretty sure that I was coming out of only the second game in the promotion series, I assumed that I had miscounted or perhaps lost track of how many games I had played. So I checked my match history and indeed I had won 6 out of the last 7 solo/duo ranked games, which makes it impossible to have lost a series. I link screenshots to some of my match history where you can see the last 3 solo/duo ranked games in my match history as 2 wins and 1 loss.

http://imageshack.com/a/img923/6049/PyoPot.jpg http://imageshack.com/a/img924/1723/24zGdV.jpg

Overall, I found it extremely frustrating to have an honest chance at promotion taken out of my hands and completely denied by a client bug.