DSTV not cancelling your subscription when requested

We cancelled our DSTV service 2nd of September 2019 telephonically. They required no other action from our side. Our last payment was also done September 2019. In December 2019 while I was in hospital a debt collector hounded me for outstanding bills for our account. They eventually contacted Multi Choice and sorted it all out. Now, 2 years later, another debt collector from CCR or CRR debt collection is hounding me again for an outstanding R150 for not deactivating my DSTV account. I ask you - HOW IS THIS POSSIBLE??? Here we are again, two years later, being pestered by Debt collectors for something that DSTV/Multi Choice did not successfully do on their side. In 2019, I confirmed telephonically with the consultant from Multi Choice that all was sorted on their side and that we owe nothing. She confirmed it. This was done on 2 September 2019. We had to do it all over again in December 2019 to make sure all was sorted with Multi Choice which it was.