Annabel,
Do you have a medical TEAM or are you the coordinator of everything? In my case, there was an oral surgeon, an otolaryngologist, a radiation oncologist, a medical oncologist, a social worker and a nutritionist on my team. A tumor board reviewed the plan of attach and approved it before anything happened. I found out dental insurance pays to pull out my teeth but not to put anything back in, even though I know of others on a different BC/BS plan that paid for implants as a medical necessity. It is tough but it sounds like you are really getting a rough deal. Is there a social worker in the oncology department that can help guide you to the resources you need?
Ed