
If I’m busy or expecting a call, I just hang up. They’ll occasionally call back. What I’ll often do is put them on speaker and let them go through their entire spiel while I continue doing whatever I was doing (computer work, making coffee, whatever). At the end of their long talk I simply say I’m not interested and say goodbye. Often the caller gets abusive, insulting, and annoyed that I wasted their time. I tell them that they wasted my time by calling against my express wishes, and they chose to keep talking when I already said I’m not interested.
I’ll usually note the phone number and do a reverse lookup when I have some time. It seems the most annoying, insistent, abusive, and nasty callers come from ‘Level 3 Communications’, an American multinational telecommunications and Internet service provider company headquartered in Broomfield, Colorado.
It’ll probably do little good, but I’m posting this on my website, Facebook, and every other social medium I can think of. Be advised: I will not, ever, buy anything, even if it’s something I legitimately, desperately need, from a company that employs telemarketers who call expressly against my wishes.