Incorect Billing - again and again............

During December 2017 I migrated my service from MNet Alanogue to DSTV Premium, and since then my billing has been incorrect, a proverbial nightmare. DSTV have acknowledged that they are still billing for MNet, dealt with the call centre on numerous occasions. The promised refund has never materialised, and lo and behold, the latest deduction this morning is once again incorrect. Customer number ********** refers - Stop Order ********** 3. Heaven alone knows why two different numbers appear on the statement and stop order. Feels like I am dealing with a state department! The call centre agents that I have dealt with are always helpful, however what happens behind the scene is a great mystery. Fix it, or I am outa here!!