MetLife trying to find reasons not to pay. I'm so frustrated and stressed

The beginning of March 2013 my Dr. put me out of work on STD due to pain in my L4 L5 bulging discs. I couldn’t bend or lift anything. I was out of work till beginning of June 2013. I was paid benefits for the duration of my leave which was the max ten weeks. I returned to work with no back issues at all but I had some pain in my pubic area. The situation I’m dealing with now is I’m expecting and got pregnant back in March. I’m now seven months pregnant and was diagnosed with symphasis pubis dysfunction. I can barely walk, I’m in constant pain and my pelvis pops and feels like its falling apart. I had to stop working in August because I couldn’t stand the pain. I filed a claim with MetLife for the symphasis pubis dysfunction and they denied it stating its related to my previous claim involving my back. Because I only have STD they were only able to pay up to ten weeks and you have to be at work for three months before you can receive benefits under std for the same condition. My Obgyn and myself have explained to them this has nothing to do with my bulging discs and is directly related to pregnancy. I feel they’re trying to find any reason not to pay. In my Obgyn records she noted some back pain, but that is only a result of the pain radiating from my pelvis. I know the difference between bulging disc pain and pelvic groin pain. So as it stands I’m still waiting for results of the appeal but so far MetLife said they don’t gave enough info proving it’s not related. I’m so frustrated and stressed. They are clearly two different diagnosis.