My experience at my appointments was fine but the ...

My experience at my appointments was fine but the billing department was a nightmare. My first 2 appointments came out to about $75 after insurance but suddenly my next appointment was $450 because the billing department used different codes than before even though it was the exact same procedure. I was told by the billing department (after calling numerous times and having to get assertive) it would be taken care of but apparently not because I was sent to collections. Insanely unprofessional staff behind the scenes.