Vodacom automated airtime advance ****

I realized on the 13th of August that vodacom just gave me an airtime advance that I didn't request. I notified vodacom immediately and requested that the transaction be reversed, to which I was told it was not possible. I told the agent that I was not prepared to pay vodacom anything more than what is agreed to as I did not consent to that advance hence, I asked them to reverse it an take their airtime back which they refused. He then gave me R20 goodwill airtime that I realized vodacom was hoping that I would let the advance issue go as a result. I told the agent that I still expect my account to be credited , he then said he would take the R20 airtime he credited me with as a goodwill gesture back, to which I agreed and further mentioned that it does not make sense that he's able to take the airtime back but refuses to reverse the airtime advance that I didn't approve. My query was escalated seeing that I was adamant about the advance reversal. Shortly he called me to say that the credit process has been initiated and I should expect the credit note soon before the next debit date but that did not happen. He constantly kept calling to tell me that the process is underway, currently awaiting approval. That was his last feedback, repeatedly saying the process is stuck at approval level but all will be rectified before the next debit . The debit order went through last night and I was charged for the disputed advance which the agent said himself that the system was erroneously allocating this automatic advance to customers. I believe this was just vodacom's way to unjustifiably enrich itself, making revenue targets *********ly charging us for things we did not consent to. If they do not misrepresent facts to lure us into taking contracts with them, then they just do as they please with our accounts simply because they have our banking details