Understand that the "No call list" only applies to legitimate businesses. Scammers and crooks regurlarly ignore it. Robo call devices are the most valuable tool of these people. Their robo caller initiates calls using a bank of several phone numbers (some of which don't exist).
1. Have a phone providing Caller ID. If you don't recognize the calling phone number, don't answer. If you have phone recording facilities and the call is legitimate, the caller will leave a message. Scammers usually leave no message.
2. Do not press 1 or 9 expecting to be removed from their list. This action only alearts them that yours is a live phone number. Do not answer or respond to the call in ANY manner.
3. Purchase a call blocker or a phone with caller ID, voice recording facilities, and call blocking facilities (many DECT 6 phones have all these).
The equipment to fight scam calls costs in the range of $50 to $100. It is worth it. There is little that state or federal governments can or will do for you. Believe me, the above suggested equipment  really works.

This caller keeps calling even after I hit #9 to opt out. The company is Verizon, and it starts as an automated call. I am on the DO NOT CALL LIST and this is about the 50th call from this number and you cannot call back the number.

Caller was "notifying me that I am eligible for an alert system".  I am on the "Do Not Call" list but it must not work.

caller ID only had ph# and New York NY.  no message

calls but does not leave vm. unknown number- suspicious