Debit order issues

My mother subscribes to DStv Premium. Because she receives a British pension that pays on a 4-week cycle, she has requested that her debit order be collected from her credit card to avoid payment going through at a time where there are insufficient funds in her current account. This worked fine until about four months ago when the debit order stopped being collected. When I logged onto her account on the DStv website, it indicated that there were attempts to collect the debit order that were subsequently reversed. However, her bank statement showed no such transactions. We tried recapturing the debit order details three times, and eventually I captured my own account, but still no success. Each time the only notification we had was discontinuation of services, and have had to make manual payments. We can now no longer access her account on the website (gives an 'unable to retrieve smartcard list' error). I called DStv on Monday requesting to speak to management