Cancellation of line

I have cancelled a line on the 12th March 2015 got a read receipt that the received the documents, the line has not been cancelled.<br> <br> I have send a 2nd request but still no effect.<br> The numbers provided to contact does not even work *** or ***.<br> We get charged for lines that was supposed to be cancelled over a month ago,<br> What more must you do that Telkom eventually start working????