Do you need a lawyer for Arbitration proceedings?

I had a problem with my treatment at Western Dental. They had to redo a filling becuse the metal filling did not seal right. The dentist knew that I was having problems with sensitivity. This problem is indicative of the need for a root canal. They went ahead a did my porcelain filling even though they should've known that I needed a root canal. Now I need a root canal and I have to have the filling taken out to do it. I also complained when my appointment did not sow up in the computer. From that moment on they kept giving me bad service on purpose. When they discussed my treatment with me they just referred to my fillings as fillings. I told them specifically that I wanted the metal ones. They gave me resin, and that filling costs twice the price. They did it on purpose. Now I want to start the process of arbitration. do I need an attorney for that?