Go to the VISE site.  They have a list of many fixes to problems that might occur including the one you are having.  The fix is to get a wood chisel, heat it up a bit and tap it into the bottom of the slug. Hold the chisel firm and twist the slug out.  I have done this and it does work.  I would guess that you pro shop might be using the old slug-it safety mollies.  If it is glued it, its the old one.  The new ones are screwed in.