How can I remove plaster board/drywall rawl plugs?
Keep pressure on the screw while you unscrew it.  It will force the plug to unfold, making removal possible.  Once the plug is fully unfolded, the screw will come out no matter how much pressure you keep on it.

If for whatever reason that fails to extract the plug, you can usually do less damage by pushing the plug it into the wall versus trying to pull it out.