Gentle Dentist Fishers

I have called the dentist office multiple times and have not gotten any answers to why they are sending me a bill and not billing my secondary insurance. The one time that they have picked up the phone the lady said they haven’t billed and the bill that I received was a mistake. This phone call took place early June and I have yet to hear back. Today I called and no one answered so I called back and left a message. On the bill it still shows they have not collected from my secondary insurance Humana but are billing me for 376.00. In my bill there is also a charge of me missing an appointment on a date that I never received notification of. I want to know why I am getting billed instead of the insurance I pay for monthly and am not getting an answer from their office.