Being charged for old handset after uprading on specified date.

I upgraded my contract beginning of June as indicated on the vodacom website as my eligible upgrade date. I upgraded online and was eventually contacted by a consultant to finalise the upgrade. I specifically asked the consultant if my monthly premium was going to be the amount indicated on the package and she confirmed. End of June my account got debited by double that amount. After speaking to another consultant she explained that the extra cost is the handset fee for my previous contract. Now in my 20 years of having a vodacom contract and upgrading every second year on the date indicated I have NEVER had to continue paying for the old handset. I am almost a 100% sure the consultant did not inform me about this cost because I would not have upgraded then. Now after NUMEROUS calls the past month requesting to listen to the recording, I am still waiting to hear from someone. Even after it has been escalated to a manager. I will be reversing any debit orders until this matter is resolved. This is the service and treatment you get for being a loyal customer for 2 decades. Pathetic!!!!