Multiple RCT, possible broken instrument, phantosmia - NEED ADVISE!

[mlw808]

I had a root canal done on tooth #18(?) several years ago. Original dentist took FIVE appts to finally get it done bc my roots were difficult and he couldn't get it done within my appointment time. Only for that tooth to bother me again months later. After seeing an endodontist, I was told I'd have to do the RCT again. Turns out I have a pretty big kink in the bottom of one of the roots that was missed and causing infection. Did another root canal with a diff doc to "finish" the job and months later I'm again having problems. This time I am experiencing phantosmia and frequent headaches (got a MRI to rule out anything brain related, all clear) on top of the aching in my jaw. Endodontist says it looks like a piece of file broke off somewhere along the way and is causing infection. He is suggesting surgery or removal of the tooth. I'm ready to yank the f-ing tooth out already, but have paid for TWO root canals, multiple opinions, xrays... and now need to fork over MORE money on a tooth that's already costed me thousands. Can I go after the dentist who is responsible for the broken file to pay for my treatment? It seems unfair that I've already paid for 2 root canals which both got half assed. More importantly, I'm smelling smoke ALL the time and the frequent headaches are very concerning. How can I get out of forking over another grand on this tooth?