Can't cancel a mobile contract after 4 months and am still being billed!

<p>I completed and sent Telkom a cancellation request for a mobile contract on 3 Jan 2017 and received an acknowledgement of receipt. Since then Telkom has billed me for Jan and Feb. I called in late Feb and the consultant assured me there would be no further debit orders. Since then Telkom has made a deduction for Mar and Apr!<br />On calling Telkom mobile today to query I am unable to reach them as their automated voice system provides an option "3" but when I key in "3" it says I've not selected a valid choice.<br />Service is non-existent</p>