Better advice is IP phone with Call Treatments. Your phone can have all sorts of capability to sift through all of these numbers. Put all of your friends in your phone book so they always get through. Certain area codes so they also can get through. All 1800 calls to voicemail except certain ones you chose to get through. Then send every other caller on the PLANET straight to voicemail. If they turn out to be someone you wish to speak to just add them to the phone book and they will get through the next time. It is one of the smartest things I have ever done and will never look back neither will you.
Called at 11:30 am today (eastern). was a robocall -- said something about this call is in reference to a credit account The call disconnected in "Ms. Robots" (LOL) mid sentence.
Told me they worked for 500 credit card companies and that they could lower my finance charge. Kept me on phone for 20 minutes then said hold and they'd be back. Never came back and they eventually hung up. I called back their number and got only music on phone!
I am constantly being barraged by voice mail messages or live calls and get hung up on or disconnected when I ask to speak with someone about getting removed from their telemarketing list. I am on the the National Do Not Call registry so, they are obviously in violation.