You need caller ID for a blocker to work. Try Amazon.com for a wide variety of available blockers. My CPR blocker allows one ring and then dumps the call.
Received call on my cell asking to speak with my husband regarding the final notice they sent out regarding our Dodge Journey. I stopped her and said remove this number from your list and before I could get the final word out she hung up on me. Number has now been blocked. Jerks.
I just received a call from this number, and only got half of the message. I heard him say "relationship. I don't know anything about it" I said I can't hear you, who is this, he said you have a good evening and hung up. WEIRD!
The 618 is a local area code. I can't block a local area code because of many legit calls, BUT I will block the individual number. These are criminal scammers who want your personal info for nefarious purposes. These people have called before using other numbers. DNC list will not stop crimals from calling, but a call blocker works very well.