Earlier quoted context omitted.
I was so annoyed by spam calls that I called my carrier and asked if I could block Texas and Florida. Apparently you cannot.
The Hiya app lets you block calls that start with a particular string. It looks like the app allows for blocking just an area code. The only downside is that numbers being blocked by Hiya will sometimes start to ring for like a quarter of a second before the blocking takes effect - still better than having them ring through. I have the area code and exchange for both of the numbers that ring to my phone automatically…
https://itunes.apple.com/us/app/hiya-caller-id-spam-blocker/...