No response to cancellation of tv license

I have sent a cancellation request by email to sabc on 12/8/15. The email was read on 13/8/15. On 25/8/15 I sent a follow up email asking for a response and to date I have still not received a response. Next thing I will be getting letters of demand for my tv license although my request to cancel is totally ignored. I do not have a working tv and no longer require a license. I wish to receive some form of confirmation that my license is in fact cancelled.