I can’t really tell what exactly you have going on but I’ve gotten buggered nutserts out by taking a small flat cold chisel around the size of a pencil and then getting it under the lip of the nutsert and collapsing it inwards on all sides. I then dig it out with pics, hooks and needle nose pliers.
If it still has a bolt in it, cut the head off with a dremel cut off wheel. Then get a pair of vise grips on the remaining stud and work it back and forth until friction and metal fatigue causes the stud and some of the nutsert to come out. Then follow the first paragraph.