Incorrect details & pathetic service

I was attended to in the ER May 2019, I was unconscious, and my sister had completed the forms. When I was discharged I saw that she had in her panic stricken state written down some details incorrectly. I sent Pathcare an email stating what had happened and provided them with correct details so they could send me an updated account with all the charges, which they did and which I paid. More than 3 MONTHS later I get another account for the same period!! I emailed and phoned asking how this was possible when I had specifically made contact and rectified my details and also a paid the account. They then said they were going to escalate the matter, this has probably happened three times for the same account. I refuse to pay as I made the effort to help them get the right details to invoice/charge me and I paid that account. I received a Final demand and today I received a phone cal from attorneys who act as Debt Collectors, they STILL DID NOT use the correct details!!! How absolutely pathetic!!