What should I do if Prudential's denial letter has several mistakes in in?

I have been on STD since Oct. 25, 2013. I pay for my Prudential LTD, not my employer. Prudential sent me a denial letter, which seems to be the standard practice. They claim the Dr’s statements/diagnosis, do not match up with my own statements of my diagnosis. I know what the Dr’s have been treating me for. I know what is wrong with me. I take daily meds for my disability. They made several incorrect statements in the denial letter. They don’t mention half of what I told them. I need to appeal. I am not able to sit or stand or walk without having pain and I am disgusted that I paid for 6 yrs for LTD and they turn around and deny me stating basically I am depressed and don’t suffer from Degenerative Disc Disease. That my Sciatic Nerve doesn’t cause me a great deal of pain. They do have at one of my MRI’s ( I have had 2) and the one CAT scan I had on my spine. What steps do I take next?