insurance help

I work for a United Methodist Church in Tennessee, we are part of a larger conference called Holston Conference. We have BC/BS insurance that Holston Conference negotiates. I just received a denial letter from BC/BS. I did a good bit a research and found that it was Holston Conference that had written in the exclusion in our policy, although it wasn't in any of the documnentation we have received. I have already written one letter to the chair of the Board of Pensions (the decision making body for insurance issues). What else should I do? I plan on writing letters regularly until they change the policy or I die, whichever comes first. Any suggestions out there? Thanls, Marc Gamble