Poor service

I'm very disappointed with the service I received from Dr. Cebekulu's office at parklane hospital. I gave birth to my son in December 2018 and after my last consultation with her, I asked how much I owed to cover any charges that were not paid by my medical aid. I settled the bill in full. Almost 3 years later, I get an sms from her attorney's threatening to blacklist me regarding an outstanding bill which no one told me about.. I'm highly disappointed and shocked at this poor service. Her office didn't call, email nor sms to notify me of this outstanding bill yet I'm being handed over to her attorneys.