Sales Agent wants me to upgrade forcefully

I have no problem with sale agents.In fact I listen to them and see whether I am interested or not.If I am not I have a right to stop them if I am not interested and we say our goodbyes.<br> <br> I do however have a problem with a Vodacom agent (Elite something) telling me I am rude if I tell them that I not interested in upgrading once my contract expires.As a consumer I HAVE A RIGHT to decline any offers especially if you called me ON MY PHONE and whilst at work.Its a pity I did not get his name but he was Indian and obviously has a problem with me not being interested in his offer.He told me I am rude then hung up because I told him I am not interested.Who is the rude one here?.Its not my problem he will not meet his sale targets.I refuse to be harassed by Sales Agents!!!