Incorrect billing amount - not rectified despite several phone calls

I have phoned dstv 6x as I can see that the amount reflecting as payment due is incorrect. We changed our payment date, actually made it earlier, but now the amount due is almost double. I phoned them 13 January the operator confirmed that the acccount is being reviewed and we need to wait patiently for the 20th and it will then be fixed. 20th account was still reflecting incorrect amount of R1965. Yesterday I phoned was informed that debit order will be for R988 although the dstv app is showing the R1965. I still felt uneasy. My husband phoned this morning was told the debit order will be for R1088. I phoned back to query why we are still getting conflicting amounts, was told amount due is R1965. I insisted to be put through to billing department, held on for a few minutes and was then told that they would phone me within the hour, this was at 10h22. Nobody has phoned me. We have tried getting a simple answer as we know that the amount due cannot be R1965 and cannot stuggle with incorrect debit order collection which is due 27th. This is not acceptable and one should not have to wonder about correct collection from your account.