Keep Players from Using Charactermancer

If this is not the place for this post please let me know. I have been running a game for some friends who are now about level 5. During each of the level up sessions I have found several problems with charactermancer and would like to prevent my players from being able to use it. One example is that one of my players (he's not very trustworthy) and I realized that he would roll for HP multiple times until he got a roll that he liked. Another player had multi classed previously and when he leveled up again Charactermancer allowed him to level up BOTH of his classes. so he went from Bard(4)/Sorc(1) to Bard(5)/Sorc(2) with a single level up. Because of this I want to stop them from using Charactermancer. Is there a way to "turn it off"? Please help.

The only think I can think of is switching to a character sheet that doesn't have support for it, like the Shaped Sheet.  I don't think you can turn it off.  

I'm not sure charactermancer is the problem. If your players are abusing your trust, there's far worse they can do with manual editing of their sheets. A player could change the base die of their weapons, memorize spells not on their list, etc. There's no way you can stop someone determined to cheat, other than to boot them out when you catch them. If you want to have total control, have them tell you what they want from their character. Make the changes yourself. Give them control of the character, but not the ability to edit. But that sounds like a nightmarish way to run a railroad.