Contract cancellation not processed - Consumer Complaint for Vodacom - Head Office

I'm so unhappy about how vodacom is handling my issue. My contract expired on the 30th of September. I called them on 22nd of September to cancel it. They told me that the contract has been cancelled. They then offered me a monthly data of R99 for 5 gig, I accepted, but later changed my mind and called after 2 days to cancel the offer. To my surprise, today I received the monthly airtime for the contract that ended on the 30th of September. I called the customer care, I'm informed that they cannot reverse the airtime and I will be billed at the end of the month. I'm so unhappy and don't want their airtime. I want vodacom to reverse the airtime on my phone as I don't want to be billed at the end of the month.