I've been searching for a few weeks to figure out what I have in my fireplace. It looks like a liner that is connected to the damper directly above the fire, not on the top of the chimney. As you can tell, it is grossly warped and rusted.

I'd like to simply get it replaced (or removed, altogether) but I have no idea where to get this taken care of, nor, what it is called. I visited two fireplace stores and they only sell gas fireplace inserts or doors.

I am asking if anyone has the name of this 'liner' or advise on next steps.