This is my landline. I don't answer that phone at all. But the phone technology identifies the caller and displays the name and number of the caller and also announces both as well.
So when it rings it tells me I am calling myself. I did send my phone company an email last night saying what the hell is going on. It's an unlisted number and on the do not call list. They are a local supplier grandfathered by the breakup of AT&T so they will get back to me next week.
I have the same problem on my cell phone as you. I'm getting calls from every town here in NC. They get cancelled asap.