It doesn't matter if you're nice or if you're mean or even if you just hang up on them every time. NOTHING you do stops telemarketers. You go in a loop. Say no? They will try back in 6 months and deny that the number coming in has called you before. Anyone who does business with a telemarketer based call is a complete moron. JUST SAY NO and keep reporting them.
So now the trend is the automated message starter that makes it sound like any regular person calling you... "Hi, this is Cheryl, how are you today?" then if you speak it'll click into their pre-recorded message... if you say nothing..... where a live person would say, "hello?"... there is nothing on the other line. So annoying!