NCAA 14 RTG question about audibles when playing on D

So I have been messing around with NCAA RTG some for a while and started a career as a FS. In my second season I finally earned the ability to audible, but what's the point of it? The game changes the play again right before the snap about 50% of the time.

For instance, if the game calls a zone I almost always audible to a blitz or 2 under scheme because zone is completely worthless. However, right before the snap the game changes the play back into a zone scheme. Is there any way to stop this from happening?