Rude Sales Rep!

Just received a phone call from a sales rep from MTN. After I repeatedly told him that I was not interested in the product, he just kept going on. I then said I don't want to be rude put I am going to put the phone down as I need to work and I don't have time for this debate. He then put the phone down in my ear. I have never used MTN before, but if there was any chance in future, guess it just got forfeited.