Impossible to cancel Telkom line.

<p>This is the second time that I'm struggling to get my telkom adsl line cancelled. </p> <p> </p> <p>I sent Telkom an email ********** on 15 Jan 2017 and they called me back two weeks later to confirm that my line will be cancelled, but today I received another invoice?</p> <p> </p> <p>This is unacceptable service! </p> <p> </p> <p>How can I escalate this problem?</p> <p> </p> <p>Account: ********** 74036</p>