As a telemarketer myself, here's some advice on getting rid of them.
DO NOT hang up on them! Most telemarketing companies aren't picky about who they hire. The result is that not everyone working there is bright enough to classify being hung up on as a refusal. The rationale is often, "hey maybe the phone accidentally disconnected."
There is one sentence, however, that will solve the problem.
That sentence is...
"Take us off your calling list."Get the rep's name and write it down before you say this (and say it politely, they'll be more inclined to listen to you). If the company calls back, ask to speak to a manager. Once you have a manager/supervisor on the phone, give the name of the rep who called you last time, explain that you asked to be taken of the list, then calmly threaten legal action. It's an
$11,000 fine if you ask to be taken of the list and they don't do it.
And while I fully support the national do not call list (why would I want to talk to people who are only going to cuss me out?), don't bother signing up for it. The only calls it will effectively stop are calls from small-time companies. Major corporations (the ones with the most irritating phone sales practices) usually have certain policies on the books which allow them to bypass the do-not-call list.
The long and short of it is this: Be polite, but firm. Don't yell and cuss, it doesn't do any good. And a privacy manager for your phone is a wonderful thing.
*Edit* If you feel like you simply must be funny, answer the phone in another language.