All you need to do is, IF you're already close to your phone, pick up and hang up, simultaneously. That way, you're not even giving them a chance to speak. Of course, this only works if you have Caller ID on your phone. If you don't, then you probably would want to answer. But I do this a lot. If I don't recognize the number, or if the area code is not from my state, then I just pick up and hang up. That way, I feel like I'm the one in control.
if you have not registered on the national do not call registry do so. once you are registered, include in your recording for voice mail that you are registered on the national do not call registry. Add as follows: For all telemarketers, my phone number is registered on the do NOT call registry so please know that I am reporting your number so even of you don't leave your number, I will use reverse look up and you are being reported for harassing me. All other callers, please feel free to leave a message and I will return your call. Thank you--------or something along those lines.
Receive calls daily from this number. When answered no one talks just silence. When I don't answer they do not leave a voice mail message. Wish whoever it is would quit calling.