Sevenster Orthopaedic Services
Paid account

My medical Aid paid Sevenster Orthopaedic Services after a medical procedure done on the 11th January 2023.
Since then Sevenster has been harassing me for payment on a monthly basis. After every email, I send them proof that this invoice has in fact been paid. And yes, the following month, I once again receive the same email.
How do I get Sevenster to stop harassing me?
Regards
JM Grobler