Exceptionally rude staff!!!

It's an absolute disgrace how your customer service treats your customers. I have been a loyal customer for years!! These days I am receiving countless phone calls in a day from MultiChoice asking whether I would like to upgrade my decoder. I have made it very clear that I am happy with my current decoder and that I do not wish to upgrade my decoder. I am still being harassed with phone calls I didn't even signed up for or gave permission for. I don't have time to listen to a 5 min explanation on why I SHOULD upgrade my decoder, so when I hear that the caller is from MultiChoice, I respectfully decline the offer and say that I am not interested. You wouldn't believe with how much hostility and rudeness I am met then, asking me in a very impolite and crass manner why I am not interested. Why I am I constantly being harassed with these type of spam phone calls and met with so much hostility and rudeness? And why do I need to explain myself to your staff?? Please train your staff better, stop phoning me and do better!!