The Do Not Call registration is worth zilch.
Telemarketers and collection scams are now using cell phones or disconnected #'s that appear as a call from your local area, ie. what appears as the guy next door to get you to pick up. Don't!!!!!
How do I know?
I called one of my credit card companies re: a disputed charge. The person I spoke with was in the scummy business until her conscience prevailed and sense of disgust. This was her introduction to "telemarketing." She confirmed this process. The person who trained her made $100,000 -$150,000 a year in salary and bonuses. This trainer, used a cell phone, which she changed regularly with other staff, and would get under her desk so she could use profane, abusive and threatening language. All of course illegal tactics as I was trained, when I was in the credit and collection industry years ago.
I also called back the "IRS" one night and a guy answered "yo, IRS agent!" True story! Quickly he confirmed it was all a scam, he got bonuses, switched numbers daily, and didn't care about talking with me for an extended period as he was "a little high at the moment." About a 15 minute conversation from overseas.
nomorobo.com Got this tip from an FGI discussion. It does work, unless it is from a cell, one ring and gone. I reported online to NOMOROBO a cell # that was being used as a false front, and I actually got a call and a message from NOMOROBO to get more details. Free service. Sign up online. They offer a cell phone service, new, but there is a charge to block scammers on your cell phone.
your phone provider (Comcast for me allows you to block calls)
your home phone often has a call blocking feature you can use
The American Red Cross has been and is the worst. I have a bazillion of their numbers blocked via my home phone feature. Still we get calls and when I Google the #, people who also received a call from that number and answer it, report it as the Red Cross.
If they don't leave a message I Google the number or do #67 to block my number, supposedly and risky, and call them back. Almost always, no company name is given or the number is not in service.
Good luck and NEVER answer if you don't know the caller. Often it is a computer merely searching for a working number which gets shared, opening the flood gates.