Discovery Health is unjust to their members

I want to Know????????

How can a person be black listed (a person who has a clean credit history) for not making a payment of R 8639.05 to Discovery Medical aid on the 1 December 2022......?????? When the truth is a Payment of R 8639.05 was made on the 30 October 2022.!!!!!!!!!!!!!!!! Proof of payment was emailed to Discovery. We were with Discovery Med Aid, The Fully Comprehensive plan, for 28 years. Due to loyalty to Discovery Medical Aid, we did not even leave them to go to Massmart Med Aid when Massmart bought the company and insisted that everyone must join their scheme. Only now so many years later, this is how we get treated. I gave the 1 months’ notice. 1 June 2022 to Discovery Med Aid as per their request as it had come to my attention that we would save R 4000.00 per month by finally joining Massmart Med Aid on 1 July 2022 with better benefits. 1 Month after leaving Discovery Med Aid, I was informed that I owed them R8639.05 through an automated computer generated message. After contacting them to request a detailed statement. I made immediate payment. I paid the full payment. Not installments. So what Now!!!