How do I get my money back after I go for a root c don't recieve one, the bridge is shotty, & Pain.?

I went in for a root c. The dentist thought it could be saved. etc. I was suppose to get it crowned they looked at my mouth and because of a potential problem got a bridge. After having the perm. bridge placed, a couple of days later the pain started. It was throbbing (the worst pain imaginable). I called they said to take antibiotics & called in Loritab. Nothing eased my pain, I had an ice pack on the whole time. I had to get the dentist in town to see me Sat. at 10pm to numb my mouth. I called the my dentist & he adjusted my bite on Sun. I was crying hysterically all the way home in pain, I went to the E.R. the nice dentist met me & numbed me again. Monday I wasn't going back. The nice dentist referred me to an Endodontist. He did emergency draining on that tooth & 1 other both dentists now say I still need a root c and the bridge was shotty with posible decay under it. Next day extraction of a wisdom tooth next to the root c tooth. It's been awful! Advice.