Struggle to close RCS account

Rcs is becoming a hassle to close my account and cancel my card. They don't answer the phone at customer care. I left a message only to be called back and told I owe R 20 as settlement. Now that settlement has been done, the customer care line becomes a ghost line. Nobody answers but advertising goes on. There is no cancelling process on the RCS websites. Fed up. Need to cancel before they add more charges on a zero Balance.