Multichoice Stop calling me

Multichoice DSTV keeps on calling me to offer me their products. I received a call today from them offering me one of their products. When I told the consultant that I didn't authorize for Multichoice to call me and I am no longer a customer and they should remove my details from their call list, she told me that Multichoice will call me as i am their previous client. This is the third call I have received since I canceled the account.

Multichoice, remove my details from your call list. I am no longer your customer and I am not interested in any of your products. I canceled my account with you and desist from contacting me.