If it didn't rotate before you started messing with it, the shoes are stuck to the drum. If it did rotate but won't now, you are stuck on a lip of the drum. Best to just cut the two pin heads off and pull the whole brake shoe mess off as one unit. Be sure to unhook the brake line and the two bolts on the wheel cylinder, it should all just slide off. If the rear bearing has gone bad and welded itself too something, you are going to have to work a little harder, but it should still come apart.
Worst case, cut the drum in two pieces.
