No action done by RCS

I have been struggling with this account since March 2020. I have paid my account in full in January 2020, Up to today (12/02/21) I am still receiving a statement showing a credit balance of R12 104.87. As I was under Debt review, I was referred to the Debt Review company and Consumer Friend. According to them, there is no Credit on their side. I have spoken to several people, Stephanie Davids advised me that there is no credit due to me. If there is no credit due to me, WHY am I still receiving a statement for more than a year stating the credit. How long will it take RCS just to rectify their system on their side, is that really so difficult. Yesterday I send an e-mail requesting a Manager to phone me back you can get these things done - No Call - still waiting.