You mean like a cork pushed into a bottle of wine, or just the bung is too far into the top of the carboy? If the latter, you can get a wire hanger and bend the tip, thus pulling the thing out.
ok , yes empty carboy, take steak knife and get a hold of Bung, now yake cork screw and get it started. once you get it started take out knife and pull out with corkscrew. All my bungs have knife marks and cork screw holes in them . After you do it once they come out easy because hole oin top is already there