Not interested - so and say: "Not interested" and hang the phone.

If it always worked. Or called me once a terribly annoying mantle, with some innovative water filters. Once, second, third, not responding to "thank you, I’m not interested". He plunged and put it on the blacklist. Hours after five checked - in the World Cup 17 missed calls, 17!After I have said several times that the offer does not interest me. It is not a sin to send such a message.