bbaker111, you're not listening to any of us.
The PGA sometimes implements what is called the One Ball Rule, which means you must play with the exact same brand of ball throughout the whole round.
For example, if I start out playing a Titleist NXT, I cannot change to Titleist NXT Tours at all during the tournament. Doesn't matter if it is in the middle of the hole, in between holes, or at the turn.
This rule is determined by the tournament committee and has been used in many major and minor tournaments throughout the world. Since it is decided by tournament committees, WGT has exploited their powers on the situation and chosen to use it.