Two years ago, I bought a $6 app for my phone that lets me block any number or any partial number I choose. It hangs up on at least twenty calls a week. I can't tell you how many times it has saved me from putting down what I'm doing, taking off my work glove, digging around for my phone, and answering it only to tell someone to get f#$&$d.
I would buy it over and over and over again. Paid for itself many times over.
It also has a shared block list with everyone else who uses it, so there are tens of thousands of numbers on there. I have mine go to voicemail rather than straight blocking it, because we do get calls from out of state property managers on occasion.
Even when it's a local area code, it's almost always an unusual exchange (2nd three numbers) so we block that part.
App is called Call Control