Cellphone deal *****

This service provider offered a cellphone deal which was not approved. There was confirmation that the deal would be cancelled but they still debited my bank account. On the 2nd August a consultant from their call centre confirmed that the debit order was indeed processed although I did not recceive the cellphone that was intially declined by Vodacom. My bank cannot reverse this transaction and now they are stalling regarding my refund. Why would I pay for a service yet it was declined. They claim that 5g of data my sent to my cellphone which is not true.