as I understood you have a hard piece of easy out broken in the hole.
you can try to destroy it using a high speed drill like this:
Proxxon Trapano fresatore industriale IB-E da D'Amico forniture
(just to give you an idea oh wich kind of tool i mean)
using carbon metal (VIDIA) tools.
I was mould maker and we used that kind of tools to drill and mill hard metal.
or you can try to drill a hole on the opposite side of the tube and knock out the piece.
it seem insulting but extreem problem sometimes need extreem solution.
mine is just a suggestion