Bad Service and unanswered questions

On the 16 April 2018 I cancelled my contract with Cell C . I spoke to Magdeline and the reference number is ********** ********** 08. In May I never recieved and airtime or data. My contract was to end 31 May 2018. I called again on the 09 May and spoke to Nontobeko to query this and to make sure my contract is cancelled. The reference number is ********** ********** 23. No airtime or data was given to me for the month of May and on the same day (09 May 2018) I recieved a sms stating "Your cancellation request was processed successfully and your contract will be terminated on 09/05/2018". My phone was disconnected and I had to buy a pay as you go voucher. Yesterday Cell C debited my cheque account with an amount of R420.26. This must be refunded IMMEDIATELY. I am NOT paying for something I never got. This is theft. I tried 3 times today to call the accounts department and had to listen to music playing for over 10 minutes