Cancelled contract but still being billed

<p><span style="color: #555555; background-color: #ffffff;">Telkom offered a new device when my contract expired and when they delivered the phone it was not what I had requested. I phoned Telkom as soon as I realised that that it was not what I had ordered and they couldn't give the phone I wanted so they sent courier company to collect the phone. I also cancelled my contract since it was still within the cooling period. TELKOM keeps on debiting my account even though I have cancelled the. I have been calling the call customer services and I was told that they won't debit my account but every month my account is debited.</span></p> <p> </p> <p><span style="color: #555555; background-color: #ffffff;">Why am being billed even after I cancelled my contract?</span></p>