Absa Card Division not refunding my overpaid amount

In May 2020 I was informed by the Absa Card OBS department that upon settling my Absa Credit Card account that I have an excess amount of R3500 which is due to be refunded to me. I was also informed that the account prescribed prior to me settling the account. Since May 2020, I have been making several attempts via phone call and email for Absa Card Division to refund me the overpaid amount, however, I had no success and not even one response to my emails/phone calls made to the OBS Department. Can someone please assist me!!