Still receiving invoices after contract period ended AND i cancelled

Hi there. I had a 2 year data contract with Telkom that has already expired. I went into a store in August to cancel it (did not upgrade and wasn’t interested in continuing with Telkom). They informed me i need to cancel online. I did so on 20 August. I received an email from Telkom saying I would be contacted to confirm this. I wasn’t contacted and nobody rep**** on my facebook message. I then received an email to say the case has been closed and assumed it’s done. But i’ve just received another invoice from Telkom. You can check my history and i do not even use the data anyways, but continue to pay. Please confirm that my contract has been cancelled. Telkom’s communication is really bad and so is their signal in most areas. I will never take out another contract with them. My husband isn’t even able to use his cellphone with the Telkom sim as there is never any service. And because of all of this along with Telkom’s refusal to assist when there are issues, I scored you 1 star. I want to make sure that i have no further obligations to you since I only signed a 2 year contract and this is now the second invoice after that period has ended even though i cancelled it in August. Thanks.