Extremely bad service - put for debt collectors for false/invalid invoice without ever being called or notified about this invalid invoice

Very poor *********** stuff with regards to how they handled my account as I'm now faced with a threat of being given a Default status for their mistake. We were admitted in 2019 and upon being discharged we went to the pharmacy section for medication and upon learning that medical aid won't be paying we then told them to cancel and we took the script and bought the medication at dischem. I recently been getting message about something I'm owing to netcare and even threats of default status so upon enquiry and calling the hospital it became clear that whoever was assisting us didn't cancel our script on the system which is so wrong as now I'm about to default for no reason. I didn't pay or take their medication and got a back statement indicating the purchase at dischem for around the same amount and same Day . Even so with their mistake they never called to indicate that I'm owing as this mistake could have been corrected long time ago but they instead quietly sent my details for debt collection without me even knowing about owing them and their ***** collector never answer their phones but keep sending sms's.