Cancellation of line

Good day We are having a constant problem with cancellation of our telkom business line.<br> We hold on for 15 -20 minutes and when we are through consultants cannot help us.<br> They give us email addresses which does not work in order for us to send our cancellation letters,and when we send a fax repeatedly no one ever gets the fax.<br> How does one go about in cancelling the business line if there is no co -operation on their side ?