Called me a little while ago, sent it to voice-mail as is done for any unidentified number. They left no message so they did not want to speak. Others state it's an electric rate change telemarketing thing. Don't know, don't care. Will not answer unless they identify themselves.
Same, called but no answer. They called twice today.
NEVER answer, even worse respond to, a number you do not recognize. Same as using the Unsubscribe for E-Mail, you are letting someone know that your phone number is a working number and they sell it to advertisers.
I created ZZZ as a contact and programmed it with a silent ringtone. Whenever I get a questionable call, I do not answer it and if I figure it to be a junk call, I save the phone number into ZZZ. This way, if they call again, I see ZZZ on my display and know not to answer it.
This was started over two years ago and I now have over 125 entries in ZZZ. I rarely ever see ZZZ on my phone. This proves that blocking these calls is worthless.
Just don't answer numbers you do not recognize. If it is important, they can leave a message.