Long Term Disability Denied - Any Suggestions

Hi,

I am the caregiver for my husband, Chuck.  Have posted a few times in the past but nothing lately.  We are currently in a situation and was hoping someone might have some insight on what if anything we can do.

He had radiation and chemo for a tumor at the base of his tongue on the left side which ended in 1 year ago.  Docs thought that it had worked, but unfortunately, it did not.  Cancer continued to  grow from the center of his tongue to the right side.    On December 17, 2012, he had the entire base of his tongue removed and rebuilt from thigh tissue and muscle;  they also had to remove part of  his larnyx and his hyoid bone.  Anyways, this has been a very, very slow recovery, but he did finally have his trach removed a few weeks back.  But now to the issue at hand:

He was on short term disability through the company his employer uses.  I was in contact with them numerous times and was told once the short term disability ended, it would automatically roll over to long term.  Received a call from the insurance company saying that they were no even going to put the claim through because it would be denied because they claim this is a pre-existing condition.  When I question them, they said that he had cancer last year and that's what makes it pre-existing.  Yes he did have cancer last year, but it never went away.  So now for the last three weeks, he has had no money coming in.  I don't know how we will be able to pay our bills in a few more months.  Is there anyway  I can fight this insurance company.  I did call his employer and they were upset and said they would look into it but have heard nothing from them in 2 weeks.  

Has anyone out there dealt with such bs from an insurance company or have any ideas on how to deal with them?  Any input would be greatly appreciated.  Thanks