DSTV refuse to pay my refund

The service from DSTV is horrible, I called on 31st October to stop my DSTV subscription as I do not have a TV in th meantime and I was advised that i was late however I can stop the debit order to go through by changing to cash payment. On 2nd November I called again as the debit order had went through and the lady advised that she will speak to her supervisor and I will receive my refund. To date I havent received my refund, I then called again today to follow up only to be told that I wont receive my refund because on their system it doesnt reflect the cancellation