fail to assist to make get back to ne even after I

I called mtn direct more than a month a ago to upgrade I was assist by Mncedisi Ntuli we did the application and then he advised me I will receive my laptop with in 5days. A week passed I called the call centre and I was advised that the only person who can help me is Mncedisi and was advices that they will send him an email for him to call me back he never called. I called the second week and I said I want to cancel the upgrade because it's taking for ever I would rather go to the store because I receive it immediately I was advised that it has already been invoiced but an email will be sent to Mncedisi for him to call me back and tell me what cud be the delay... HE NEVER CALLED ME BACK I called the fifth week and spoke to his team leader she advised me that the delay was caused by a payment not received which I was not aware she said I have to pay R529 and asked me to send her a proof of payment via email which I did. I still didn't receive my laptop apparently I had to pay another R18 a week passed I still receive my laptop. I called again today and was adviced that the laptop was retain and I want to cancel the contract I have been billed for something I have not received!!!