Impossible to cancel

I contacted your call centre and spoke to a consultant about cancelling my ADSL line. I was sent a form to complete and send to a cancellations email address. I was aware of the 30 day notice period. I sent the form to this cancellations email address on 15 December. I heard absolutely nothing until I got my invoice for the period 8 Jan - 8 feb 2016. I then emailed the same person I had spoken to before (Lawrence Goba), and all that happened was he forwarded my email to the same address, as well as some \escalations"address. Again... NOTHING. I have mailed all 3 of those email addresses (Lawrence Goba and cancellations and escalations) AGAIN"