Caller ID "Name not found"

another spammer from overseas.   folks who obviously are not aware than NO telephone exchange in the USA begins with the number "1".

This number appeared on my caller ID several times recently. I did not answer and no message left. However, today I answered and it was someone trying to give free estimates on house or yard projects. I told him I had no projects and did not like the repeated calls, not to call. Tried to say we are on the do not call registry but he hung up.