You have to call them back multiple times (they will hang up on you when you tell them to take you off the list) then threaten police action.  I did jsut that and they have taken me off their list.

I have been getting numorous calls from these INDIAN LOSERS asking me about male enhancement...I have told these LITTLE DICK [***] over and over again that I have never requested anything about making my dick bigger cause it is just fine the way it is! I have told them to call their own kind cause they are the ones that need male enhancement! I called my phone service and had a block put on all the dumb [***] numbers that they have called me from! I'm sure these people will still call from another number. I have asked numorous times to take me off the call list and they find another number to call from. I wish I had nothing better to do then to call random people and harass them.

I'm on the Do Not Call List . . . . . . Why am I getting calls like this all the time?! I don't answer, they don't leave messages either. I'm getting really irritated by this. It needs to STOP!!!!!

If when they call and just hang up, how do you know what they are selling? This is was way for hackers to try and steel info, just like unsolisated mail on your computer.

They won't just go away... The only thing you can do is put calls blacklist on your phone and block the number for the next time that number calls you. However, they have thousands of numbers they call from.
I was told if you answer it is a way they can hack your phone... if you don't know the number, don't answer it.