Not getting a prompt response on emails

I received an sms telling me to pay my acc which has been handed over to legal, I made a payment and sent through a proof. i didn't receive a response and 10 days later i followed up and they told me that there's still R677.20 outstanding. i then requested them to terminate the contract and send me the final figure to be paid , still no response. i followed up again on the 30th September 2015, they responded saying that there's another outstanding amount to be paid and i must refer to the attached statement ( it was not attached) . i responded immediately requesting the attachment and no response. i get read receipts but no response for this email. i really need this resolved. Can i get the final statement so that i can settle the outstanding amount and port my number to another provider?<br> I am really not happy with MTN Service.