Won't cancel my expired contract. Still billing me

My data contract with Telkom expired Sep/Oct 2015. On 19 Dec '15 I went into a Telkom Store (and waited forever) to cancel contract. With a month's notice the contract was supposed to terminate on 31 Jan.<br> <br> I received my latest bill and found I am still being billed for Feb'16.<br> <br> I phoned the call centre and the lady was completely useless and not helpful (I did lose my temper - sorry!). She insists that my billing is for Jan, even though the invoice states Feb. I took her back from my first bill and traced through every month to show her that I am in fact being billed for Feb. By the end of the call she still insists the billing is for January.<br> <br> That being said I then asked the lady to confirm that I will then not be billed for another month. She then confirmed that my contract is still active and has in fact not been cancelled. She confirmed that they have received my cancellation on the 19th but the cancellation will only be done after the retentions' department contacted me. She cannot help with them contacting me and can only escalate.<br> <br> I asked to speak to supervisor and she promised a supervisor will phone me. This never happened.<br> <br> This is a huge contravention of CPA!