Sounds like the panhandlers in my city.You can't win. I used to give them a chance to go through their spiel before telling them no. Then one time a guy got pissed that I'd "wasted his time" letting him go through it all instead of saying no up front. WTF?!? I'm talking so aggressively pissed that I had to call the cops. And arm myself. It was really crazy.
So now, if one's lucky enough to pin me down (like while I'm doing work in the front) I just tell them no up front and if they give me that "but you don't yet know what I'm selling" BS I just tell them I don't care. If I'm feeling polite.
AT&T has been very aggressive in my neighborhood lately. If they don't catch you the first time they keep coming back. The other day I heard The Wife tell them no like four times and they kept asking to speak to me instead. I so much enjoy the look on their faces when I tell them to F off...