Search the Forum, as this has been discussed a lot. You can find out what you have to do to keep it from happening. If you have had it happen 4 times since the system changed, you haven't got it figured out yet.
This is the latest thread about the problem. Try this link:
430560.aspx
In the thread above, I've copied below what Yankee Jim said:
"The problem is with starting the round before the day changes and finishing it after the change. This no longer satisfies the CDP requirement.
You need to start the round AFTER the new day starts and it can't be multiplayer games. You used to be able to play right through the day change and get credit for having played the new day. That is no longer. I have personally verified this. :-("
For what it's worth, I make it a point to play 1 random hole on the course of my choice (pratice mode) just after the new day starts, which is 7 PM Eastern time and 4 PM Pacific time. I have played 356 days without a problem using this method.
As far as CS, I doubt if they will respond as they can see it has been discussed repeatedly in the Forum.