Refusal to refund even after they confirmed that its *****

I am a Vodacom customer and not happy about the service. A ***** was conducted in my account with Vodacom and after investigation Vodacom refunded me. That in January 2019, I went to Alberton Vodacom and took a Tablet for my son and they agreed that i will pay R249.00 per month under tablet no ***. That on 01 February 2019, they deducted as agreed the amount of R249.00. That on 01 March 2019, they deducted R7 483.21 which is above the amount. I went to Alberton office again and was told the person who assisted him has resigned. I was told that query has been lodged under ref no ***. Vodacom is failing to refund me the money which they deducted. They confirm that it was ***** but fail to refund me saying they do not pay cash to customers. I want Vodacom to payback my money. Vodacom to refund me