Pushy salesperson

I received a call from MTN this afternoon that I really didn't appreciate. First off, it was the third for the afternoon. You'd think after I rejected (not just didn't answer) the first two without answering they would get the message. I only answered so I could tell them to not call again. First I was told I'm "one of fifty people selected" for this offer. That already makes me angry because we all know it's not that exclusive, they're calling everyone. So already I don't want what they're offering just because of that. Then the lady tells me I can get data for much cheaper in this offer than buying each month. I know that this is a contract thing and I'd rather not be roped in. I told her no thanks, I'm not interested. She then said but she can see I buy data every month and if I get this offer I'll be spending less. I told her that I've recently changed my circumstances so that I'm accessing Facebook on my computer, which is what takes most of my cell data, so I will no longer have to buy (as if I even need to justify myself?!). She then became very pushy and started asking well that's when I'm at home, what about during the day? Actually, that was during the day, at home I'm on wifi. She kept asking questions and trying to push this product on me despite me having said three times that I'm not interested. I understand that she has a job to do and this is how she makes a living. My issue isn't so much with her calling me. My issue is with how insolent and pushy she was after I stated very clearly that I'm not interested in the offer. Questioning me about my personal circumstances. Using a disbelieving tone when I said I'm no longer going to be purchasing extra data. I'm currently not sure if I will definitely no longer be buying data each month as I've only had the computer access for one month. It may be possible that going forwards I still have to buy data. But I can guarantee that I will make sure it's not through this plan that MTN wants me to take and that I will make sure that I spend less on extra data than I would have on that plan. MTN, you have really made a customer irritated here. Because of this call I'm going to go out of my way to avoid your extra add ons. Train your staff better. Let them take a "no" as a definite, not a "persuade me".