Met Life insensitively thinks "everyone has back pain"

Hello, I am a 30 year old female with chronic pain in my lower lumbar that is a result of severe disk degeneration, arthritis throughout the spine, a bone missing in the spine, torn discs, herniated discs, buldged disks, pinched nerves and several other issues. Due to the low success rate of having surgery to correct the compounding issues, the neurosurgeon enrolled me in a rehabilitation program that not only looks at the physical aspect to chronic pain, but mental as well. Insurance fully covers and supports the rehabilitation program, but I am having issues with Metlife seeing this program as a reason for disability. Due to my company’s plan of only paying 65% of pay while on disability, I decided to work 2 days a week with strong work restrictions and limitations. It has been two months; my doctors (yes multiple) and myself have submitted everything that was requested and then some, but Metlife keeps denying me for reasons such as “everyone has back pain” and “why can I go to the program but not to work” (one of those coming from the manger of the Case Manager’s). – Not only has MetLife continually been insensitive, they conveniently “misplace” paperwork and will admit to misplacing paperwork that delays the process for an updated review. I have a log of everyone I’ve talked to, when, times and what was said on THEIR recorded line. Is there anything I can do? I’m desperate!