Sounds like the glow plug is frozen.  Stick the glow plug wrench back on there and try again.  If you can't remove it, you will have to replace the button anyways, so try as hard as you can.  If that doesn't work, get a socket that fits the glow plug, a short extension and use a rachet to remove the plug.  You will get alot more torque on it that way and it should break loose.