SABC TV license department Harassment

I have had a TV license for more than 30 years now. When I got married we emailed and phoned SABC license department to cancel my husband's tv license as I already have a license. My husband have subsequently been getting letters of demand from lawyers for outstanding licence fees. We again sent the proof of my licence and enquired why a single household needs two licences. My husband still get almost daily SMS demands and phone calls to pay the outstanding licence fee. How can I stop this harassment.