Beware of drs du buisson labs

Good Day. Please be aware when dealing with this lab. My mum went to them in 2022. They charged he R 2000 for a full blood count test. She paid them in full. I then began receiving messages from them saying I'm owing them in excess of R2000. I ignored it and hoped that they would find their mistake. But they continued sending me messages. When my mum needed blood tests again., they refused to help her until the account was cleared we paid whatever was owing and she did her tests and we paid cash for those. Now recently, I'm again receiving msgs from collection agents saying that they are having me blacklisted. I called them and they maintain that I am still owing them money. I refuse to settle this account for the third time.