Account no being settled

Last year 16/08/2017 was admitted in hospital it happened that i under went Audiology Consultation, at that time i was still admitted. To my surprise this year January i received a call for a Doctor informing me that i was owing them, i contacted Bonitas they gave me a ref 230118QAZ559 said i need to call them after 7 working days yesterday , this morning i received a reminder from the Dr stating this: Good day

This is a reminder to kindly settle your account. Please note that accounts exceeding 120 days will be handed over to our debt collectors. I then called medical aid again was told that i need to contact the hospital ask them to use a different authorization code so that they can proceed with the payment i called the hospital they said they wont be able to do it i need to talk to mt Medical aid.