Pushy and unpleasant telesales person

Vodacom needs to tell its telephonic salespeople to dial back the aggression. I answered the phone even though it was an unknown number - because I am waiting on someone to get back to me on something else - and gave the guy a chance to say his piece. When I found out that it was a Vodacom call, I then said quite explicitly that I do not like to take calls from Vodacom telephonically, because I have been caught out in the past and end up taking products I do not actually want or need. I said quite explicitly that I now only work on my Vodacom account by going into the shop. The salesperson became very pushy and borderline aggressive - he was talking over me when I tried to explain and then even raised his voice, forcing me to put the phone down on him, which I do not like to do to telesales people because I do try to show people respect. This guy needs to be told to listen when someone says they do not want to talk to you. The call came in at +/-08:40 / 08:45