Dr Ngwata can't provide a invoice for payment received

My aunt went to see Dr Ngwata at Netcare hospital on the 11th of March 2026. She paid her part for the wisit on 11 March 2026. My aunt only gets a government pension and she have Oneplan medical insurance not much but its something. When payment was done they gave her a receipt, and said they will send her a invoice so she can send it to Oneplan. We are still waiting for the invoice that is required by Oneplan. Yesterday the 19 March 2026 my aunt had to go for x-rays and Oneplan didn't want to load funds because they are still waiting for the invoice. I contacted Dr. Ngwata's office the ask why its taking so long for them to send us a invoice. The lady by the name of Rebecca told me she did gave my aunt a receip and they will send a invoice as soon as possible. I waited and call them back again but they didn't answer so I contacted the hospitals liaison group and they also struggled to get them to send us a invoice. After a few hours I was informed that they have sent me the invoice but it was the wrong one and they said they would try again. This morning 20 March 2026 they said after struggling with Rebecca she said she have sent me a copy of the invoice and again it was a copy of the receipt. The more I asked for it after contacted Rebecca, the more she said she will send it again she didn't know I was looking for a Invoice. I also contacted the assistant to Mr Richard Mulder, Connie Basson to ask for help, because we cant claim for anything until proof is given to Oneplan. Connie Basson said they dont get involved with Dr and its our own responsibility, this Dr is working for the hospital and they can't even give you a invoice. This same Dr told my aunt that their is something wrong with het hips not knowing that she had a replacement. When my aunt told her its a hip replacement she just kept quiet and said she must go to a specialist to have it checked, that's why we were getting x rays done for the specialist. We saw a specialist yesterday and her hip replacement is 100%, just saying.