********** Contract Upgrade Not Resolved

I am not receiving a good support from my "favorite" Cellular network service provider. I had a contract with them. A ********** upgrade of the same contract took place. When I went to add a line at the end of the contract, I discovered that this ********** upgrade had happened. I followed the correct channels as advised by the Vodacom outlet shop. I was promised the issue had been resolved, the debt I owed due to the ***** had been reversed. I recently requested to receive statements on my email. It turns out on this statement, I am still making payments for the **********ly upgraded phone, despite the effort, the endeavors I made to get this rectified. Where do I go from here now, because Vodacom is not sorting out my issue and yet I am owing Vodacom.