We wanted to briefly let you know that this is a bug and one that only affects the way your points are being displayed. In this instance, the problem can only occur when you finish a game across a season roll and will only be reflected in your match history. We can confirm that no ladder ranking position was lost as a result of this issue.
Our apologies to those of you who may have gotten quite a scare from this one! We certainly understand your cause for alarm. Rest assured we will correct the display issue for the next season roll.