Well, first of all my husband took care of that - he can be pretty intimidating when he wants to (it's a eral talent). But he was basically relentless, refusing to give up, going from one supervisor to the next, and stating that we will not use TWA ever again. I also think it has helped that we were planning on buying one ticket (which have not done at the time), stating that we will fly another airline. Obviously, that will not be helpful in your case, but I would just refuse to disconnect and talk to as many levels of supervisors as you can.
Roni