BILLING KEEPS ON GOING WRONG

On the 09/06/2015 i sent a POP and copy of the Cancellation Quotation to the Retention's department of R 526.29 as a request to cancel one of the Handsets that i had on contract with the same number as i did an early Migration. The email was accepted by no call was returned to say if something was wrong with the amount. On the 09/07/2015 i checked by balance and it stated R 859.60 for a contract that is suppose to be about R 200 Samsung Tab 4 1 Gig. I called the Accounts and they logged a query with the ref: S3-8AD2Q-QGE8I. I was told i'll get a call within 7 days. No call, i returned another call 9 days later and was told 24 hrs. i'm suppose to pay the bill on the 31/07/2015 but no one wants to call me and rectify the mess that was made from the beginning of this contract. Every month i log a complaint against Vodacom and they credit. I don't want any credit until i get a call and if not, they can cancel the contract and come and collect their phone.