TV licence cancelled Ignored

I have cancelled my sons tv license on his behalf (have letter of authority to handle his affairs) he moved to Christchurch in May 2014. I have send two emails in to them advising them that he left the country and the tv now falls under our tv licence,.<br> They never took the time to come back to me. Now they send him an statement for R927.50 that he needs to pay. I have forwarded the two emails to them and told them that i have notified them and they just argue he should have done that prior to leaving the country.<br> What does it matters who advised them i have proof that they were advised of this change and they ignored the change.<br> I have given all my details in the email and they did not contact me.