Still being billed, 3 months after cancellation!

Well hello again Telkom, I really am getting rather fed up with your absolutely useless accounts department - When somebody (in this case me) cancels an account with you (in January already!) and you confirm that everything was closed and paid in full, your accounts department should STOP their debit order instruction for said customer. Continuing to run debit orders can be considered as ***** and that is against the law. Now as much as I would love to continue pointing out the very obvious to you and informing you how to do your job, it is a waste of my time to have to do so every ****** month... I have instructed my bank to return the debit order that you have yet again lodged against my account - Please inform your accounts department that I will not pay another single cent to them. If they have a problem with this I will gladly provide them with my attorney's phone number. Kindly provide me with proof that my account has been closed and commit to STOP robbing me. The last reference number that I was provided with was 464662 (Which I got after going in to a Telkom branch in person to try to resolve this issue.) I've tried everything I could and feel that you've dropped the ball