Vodacom **********ly over charged me

I took insurance when I was upgrading my contract and vodacom wrongfully over charge me when I saw the charges I contacted them and they told me it's a system. But now they don't want to fix this the Want me to pay the amount so that the will bill me back when I refused the don't Want to fix it they say they can't u till I pay which is they want me to clean up their mess and they refused to give me a ref no. I spoke to a lady called Kutlwano who refused to transfer me to the team leader on the 7 Dec When I spoke to Nthabiseng she said they escalated the matter, I contacted account department and they don't see the escalation and the requested a ref no which I was not given