Overcharging/sending no invoices altough I already paid!!!

My daughter had an emergency treatment in the Netcare casualty on 1 June 2021.

I paid R1640 immediately. I have proof of payment. I never received an invoice for that although I have queried this several times!!!!

Yesterday I received a sms from ER consulting. The SMS sends a link. When opening the link you get directed to a payment app and I get charged R1008.60....also there still NO INVOICE . Unacceptable and *********. I have already paid R1640 so there is a refund due to me. I ALSO NEED AN INVOICE WITH CODES ON IT AND PRACTICE NUMBER URGENTLY!