Unprofessional and Rude Dentist

This dentist overcharges for his services. I have been harassed about settling the account - since my medical aid did not cover for the dentist appointment. Their accounts department did not do a proper follow up after the medical aid rejection - waited over months and now I get daily calls and emails to settle the account, of which they are rude and unprofessional. Where am I supposed to get the money on the whim???? I would never recommend this practice.