I tried to cancel my landline and internet with telkom

I tried to cancel my landline and internet with telkom. I gave 30 days notice. They confirmed that only the landline was cancelled not the internet. I keep on calling the client services and get switched from one consultant to another. I eventually spoke to someone who confirmed that the cancellation has been sent through and that the account would be credited and closed. I just received another invoice to say the line is still active. Please get someone to call me and to close and cancel this line immediately. I am not going to pay for something I was not using.