When I got a VOIP phone system a couple of years ago, I got a new phone # that is not listed. This stopped all unwanted phone calls. No more calls from charities, politicians, or telemarketers that probably use the Do Not Call List as a source of phone #'s to call.
My prior phone # was on the federal Do Not Call List and yet I got similar telemarketer phone calls a couple of times a month that could not be stopped. The few times I did respond to telemarketer calls to point out I was on the Do Not Call List, they obviously did not care. Reporting their violations did not stop the calls. Also, charities and politicians are apparently allowed to call anyone they want. Asking them to stop was completely ineffective.
For me the effective solution was (1) a new unlisted phone #, (2) I did not list my new phone # on the Do Not Call List, and (3) I only give the new phone # to businesses and people that I want to be able to contact me. The robocallers don't call you if they don't know what your phone # is.