Horrible Serivice. Incorrectly Handed Over

In May last year my I took my wife to Netcare Olivedale (Johannesburg). She was in an accident and needed a check-up. So on the day she only did X-rays (which we paid for in full). We left the hospital and assumed that everything was paid for. Come end of the year NuDebt Management reaches out to us saying my wife has been handed over to them because of non payment for consultation. ER Consulting never sent us a bill for the consultation. I spoke to 1 of their employees today named Thabo who said that they sent the bill in October last year via email yet my wife has no email with this invoice. Also, why would you only send an invoice 5 MONTHS LATER! Anyways, happy to pay but this admin is horrible. No acknowledgement of how they mishandled this. No invoice received from ER Conuslting, and they claim they only sent us the bill 5 months after the fact. So ultimately they handed us over without even sending us the invoice. This should be *******.