Still being debited for a contract / phone I don't have

Mondo contacted my husband with regards to a MTN offer with a Iphone....he never agreed to the contract as he had asked the gentlemen to call back....he then received the phone which was not the phone he had even discussed. We were asked to return the phone to the closest MTN which we did on 23 May, and we then called to find out if all was cancelled we were advised it was. 2 debits have now gone off his account...we have asked numerous times for this to be cancelled. Please could you get back to us or I will need to report this to the CPA.