NO GRACIAS! explain to me

I would also like to add that in our own countries, wether it be Australia, Canada, USA, Enland or France we also get many many people trying to sell us things.
It is normal for us to just politely say " No, thank you " if the item being offered is not wanted. I'm affraid it is neccessary for sales people at all levels to expect that some people will not want their products, and indeed, get quite frustrated if they are continually telephoned, door stopped or approached to buy shares, cosmetics, time-share, cleaning products or ceramic toys etc.etc.
So, whether you like it or not, if you plan to make your career in sales, you will need to learn to sometimes be 'thick skinned ' and take the rebuffs with a smile and just move on. Also if you interrupt, or expect immediate attention just because you are speaking to them, you must understand that people have no obligation to reply to you.
However, do not accept downright rudeness from them.