There is a medal system separated from the achievement system in this game. You will be awarded a medal when you meet the requirement of the medal. The counter shares with Windows 8 version of this game. Play one more game if you already got this number of medals but the achievement doesn't unlock instantly.
Important note: In the first version (Dec. 27, 2013), all these achievements are partly glitched. You must win the 4th medal on your phone in order to unlock the corresponding achievement; if you already missed that, please wait for the next update.