Bankmed bad payments

We have been with bankmed for years, no problems and good service. We pay a big monthly membership fee. My daughter went to hospital to remove tonsils. I called and got authorisation. Now I am getting bill after bill from clinic, and doctors mentioning bankmed only paid about 30% and I must pay difference. What?? This has never happened with bankmed. Are they bankrupt or something? Why are my hospital bills not being paid in full after I paid the Co payments beforehand?