Failure to cancel account

I cancelled my line/account on the 3rd of October 2015. I payed my final invoice. I again contacted telkom and found that my account hasn't been cancelled. I phoned the call centre 4 times to try and cancel my account and everytime they tell me that an agent will contact me. I still receive invoices and yet again i sent in a cancellation form togehter with a copy of my ID. And yet again nothing is happening. This is absolutely pathetic. I cannot afford to keep on paying invoices for services I no longer use. I am a Student. <br> <br> Please cancel my line!