Moen handle problem!!

I went to change a Moen cartridge and of course the 1st step is to remove the handle screw. Using a phillips screwdriver, I can turn the screw while holding the handle but it won't UNSCREW - it turns as apparently does what it's attached to. I have put pressure on the handle to help pull out the screw but no luck. I figure that I have to crack the plastic handle off??? I don't want to damage the screw neck of the cartridge that is in there so that my Moen removal tool will attach and remove it properly. Please HEEELP !!!! A 10 min job has turned into a nightmare. Thank you

The handle must be broken already, so just cut it off.

The handle isn't broken though. The screw just won't unscrew. But, if I do as you suggest what's the best way to "break" the handle off. Again, I want to be able to attach my Moen puller to the bad cartridge by screwing the puller into the "necK" of it. Isn't that what the handle is screwed into NOW??

If the screw turns freely, it may be broken or the threads stripped. If this it the case, there is nothing other than gunk holding the the handle on.

The handle is broken and the screw is spinning along with the center spindle of the cartridge.
So yes bust out the handle so you can hold the spindle of the cartridge and prevent it from turning while you undo the screw to replace the handle.

The handle IS broken internally, otherwise it would prevent the stem from turning when you twist the screw.