I used to be a telemarketer. which is a great job by the way... fun as hell.
that do-not call list... anyone your a customer of dosent have to respect it. in there minds, and in the eyes of the law, business have the right to call their own customers.
IE: your phone company, your bank, your credit card provider.
its kind of lame, but thats how it works.
and if your asking a telemarketer to put you on the do-not call list. Do it polietly. if you just say "Dont call me again" and hang up. theyll probably just put you on the recall list just for shits.