Has anyone replaced the flange that holds the two bolts that go thru the toilet to hold it down? I think it is called a closet flange Mine has all Phillips screws, but one of them has the square hol...
Have you tried using a square head bit with a small socket and a ratchet. You might be able to put more downward pressure on it. It might be a number 2 or 3 tip....can you get a pair of vise grips on it? Just some suggestions....