If you drilled the case out to remove the expander plug you've probably drilled too big a hole to use the tap that's employed in creating a threaded hole for using a store-bought stuck case removal tool. Perhaps there's enough meat there to tap for a larger bolt than the 1/4-20 normally employed? Maybe a 5/16 or possibly 3/8 threaded hole, and then jerry rig a bolt with a stack of washers and proceed as normal? In future don't drill out to remove the expander, not necessary.
Look at a pic of the RCBS stuck case tool and you'll see how it works and you should be able to execute a workaround with a larger screw. I've removed some stuck cases over the years by using a 1/4" tap, 1/4" bolt and a stack of odds and ends washers - no need to give RCBS any more of your money than necessary!
True Gnoahh, one thing I found is that the 1/4-20 bolt that rcbs supplies isnt long enough to get a really stuck case out as not enough threads catch in the brass. Found that the stack of washers on top with a longer bolt gets in far enough to grab real good. Probably ruin the rod but he’s already done that. Tap and die set and a knack for afro engineering helps.
Ohh, and buy some Imperial sizing wax. Ive only had to use mine once when I tried One Shot.