Consider getting a call blocking device or phone.. You can google them and many are around $40.00 or so. If its a cell phone, some already have call blocking, if not, there are free apps on the web that will work for some. You can google this. If you have a smart phone, there is a free app called call control. Iphones appear to have apps also. Another one is called Mr. Number.
They called my cell three times this morning, even though I'm on the no-call registry. It had something to do with a political survey, but they would not identify themselves, and the caller was 'not at liberty' to say how I got on their list. When I pursued the questioning, she hung up on me. The ID said "Bridgeton, MO".
The Do Not Call registry only applies to sales calls or attempts to qualify you as a sales prospect for a 3rd party. Surveys and political calls among others are exempt from screening against the list before calling.
Called twice in a 2 hour span on our landline. Caller id is "missouri". Since unknown caller, we don't answer. We get so many of these unknown calls that we just don't answer our house phone any more unless we are 100% sure we know who is calling. It's sad but it's come to screening our phone calls.