Handed over to a debt collector

Since 2012,I have been back one forth with Bankmed,Had my wisdom's removed,there was an outstanding amount which needed to be paid to Dr Danka. Now the Dentist has handed me over to a Debt Collector to have an amount of R1 928.47 that was not paid by Bankmend.I have called on numerous times and have sent numerous emails with no proper feedback from Bankmed.We are on a Comprehensive plan and the plan does cover the cost. NOW I HAVE THE DEBT COLLECTOR CALLING ME TO MAKE PAYMENT.