Poor Customer Service from Vodacom and query is now outstanding for 3 months

I have been with Vodacom for many years, in fact since I have starting using a cellphone. I have never missed a payment and have upgraded numerous times. I went into the store to upgrade, discussed with one of the floor salesmen and explained what I need. He suggested the OPPO. When I got to my IT department at my work it was discovered that the phone is not compatible with the security requirements. I made it very clear what I need to use on the phone when I upgraded. I went back to the store insisted that I "swop" the devise and was given a Samsung. It is now 3 months later and the credit on my account still does not reflect. They have deducted R 12586 from my account 2 months in a row, which caused my other debt not to go off my account. I have to go into the bank to reverse the debit orders which will affect my credit score, and I have never been behind on my payments. I am penalized for Vodacom's mistakes. I had no choice to cancel my debit order which I yet have to receive confirmation from Vodacom that it is reversed. Numerous service requests, phone calls, store visits which interferes with my work and it is still not resolved. I get harassed 3 to 4 times a day to pay my account and I dread that my account will be blocked. Cicil who is the manager at Northgate is also unable to resolve this issue. I have written to the CEO with NO response. This is an utter frustration and poor customer service. I have no idea how this can and will be resolved, numerous Service Request has also been logged. We get transferred from the one department to the next without resolution and there is NO ONE to escalate to.