Unable to terminate contract

Contract cancellation form was emailed as directed on Telkom's website on 22-Nov-2017, giving more than 21 business days time for Telkom to cancel the contract at the end of the 24-month period (on 30-Dec-2017). I made contact with Telkom 4 times prior to 30-Dec-2017 to ensure the contract termination would happen. On 21-Dec-2017 I spoke with call centre agent Bohle who confirmed that the cancellation has been logged and the service will be terminated on 30-Dec-2017. It is now 23-Jan-2018 and I still have internet and have been billed for January. I have made contact with Telkom 7 times in January and no-one has assisted me at all. I beg you to please help to resolve this issue immediately as it has been 42 business days since I requested the termination of the contract. I will change the rating of my review if you are able to assist in fixing Telkom's error. Please do not just log a normal case or get a call centre agent to call me because they are clearly unable to help. I need somebody who knows how to fix this, or else need to speak with someone directly from the cancellations department.