Struggling to cancel my TV license

I have been trying to cancel my TV license since 2012, without success. By now I have resigned myself to the fact that I will probably not get it cancelled. However the last few months Nudebt started hassling me to pay. I am fine ignoring the SABC since they are ignoring my cancellation requests, but the weekly phone calls, emails and SMSes from Nudebt is getting irritating. Is there any way to get rid of the SABC once and for all? I am not going to pay for a license of a TV I don't own any more.