Unum's stalling will force me to either sell the house or the car

My husband had long term disability for about 5 years with UNUM until about 3 months ago. He received a letter from them stating that his pain doctor checked something stating he could go back to work. (History) After multiple back surgeries the last one in 2010 the doctor fused his lower back and in the process he severed his sciatica nerve. With this my husband could no longer stand or sit for long periods. He has a constant shooting pain from his left buttock down his left leg. It has affected his sleep, his health and many other things that I will not go in detail about. Since the pain doctor made this major mistake on his paperwork he has been denied his disability. Unum told him to go to a doctor and get another complete physical. After a 750.00 bill and 4 hours of painful activities Unum is still him-hawing around. They told my husband it should take a week. Then they said they needed more paper work from the doctor. They got that, they told him it should be 2 to 3 work days. On the third day my husband called them back, this time they said they were checking on the doctors credentials. 3 more days, he called again, they claim they are still checking his credentials. Still nothing by next week we are going to start having to take drastic measures on our life styles. I am not sure where to start, sell the house, file bankruptcy, sell my car? I am hoping it don’t come down to this but after reading this website sounds like it just might happen. Any suggestions would be great. We have been very polite with them thus far and we are not ones to call a lawyer for help, but we are getting desperate.