After Months still struggling to cancel my ADSL Line

Even after writing a previous report and dealing with the "Telkom HelloPeter" (which I must add are as useless as the call desk agents) I am still not having any joy canceling my telkom adsl line... They say it has been cancelled and should just send my last bill and they will refund me accordingly... But good luck getting a reply from anyone! 5 Emails later and still no joy... I am seriously starting to think that they do this on purpose to skim the interest off your money in their accounts... Actually to the point where you could almost call it *****? How can I get hold of a person who will actually sort this out for me once and for all!?!?!