Upgrade incompetence - Consumer Complaint for Vodacom - Head Office

I upgraded in june and when i did the upgrade i was told that there is still one deduction outstanding on the device, which not only is this the first time i heard this happening when upgrading and it seems none of the agents that i got through was able to assist or understand. So now i am sitting with another invoice for the 2nd month in a row where i am not only being billed for the device but also contract insurance which i have been struggling to cancell since last month? I am at my wits end as it seems that no one can assist me