Charged an office fee without consent during physical

Hi everyone apologizes if I didn’t select the right tag.

I had a standard physical appointment last month (in CT). My doctor brought up causally how my headaches are doing as I have post concussion syndrome for 5+ years. I told her I’m still having them but managing fine. She then asked about my asthma and I stated if we could do a refill that would be great. She proceeds to send my info to a headache doctor and refill my prescription which I say sounds good fine.

I just checked and saw I have a balance for an office visit as these 2 items aren’t part of my physical. My question is shouldn’t the doctor state when and if something will cause a fee? I used to live in NJ and have brought up the same info and not charged anything; my doctor also at the time notified me of what can/could bring up a charge.

I called my insurance company and they confirmed because I spoke, even though the doctor brought both of those items up, I was charged a patient visit for the 2 items. How do I avoid this happening again?