Telkom Salesperson Poor telephone etiquette

Just got a call from a sales person trying to get me to take a new contract ..His name was Husain did not like the way he was forcing me to take a contract I didn't want . After 10min he should have understood I'm not intrested but no he wants to be rude and insinuate that I'm not smart cause I don't want to take a new contact... If I want to spend more on my telkom account can I be left to do it in peace without sales people pestering me..I was very offended by his approach please teach your staff properly.