what type of lawyer do i need for medical insurance claims

I have medical bills that the insurance company is denying. My dr told me that I had to have 2 procedures done in the same day, and nurse left room, returned stating that it was covered by ins 100%. The next day I received call from hosp stating that it would only 80% covered. I checked with ins co and told them what I was having done and they said it was only 80%. Reluctantly I still went through with procedures. Now ins says that they will cover 0% since I had them done on the same day. At no time was anything ever discussed that the procedures could not be in same day. The nurse never checked with ins (only called automated sys to see if I had a deductible) and ins never told me when I called them. Now I have over $20000 in bills and not sure what to do. I would never have had both procedures done if I knew this.