Keep getting call from 224-223-7127 for the past several days; initially speaking a language I couldn't understand, so now I ignore the call. The caller doesn't leave a message and it is very annoying.

Stop calling me my number is unlisted and stop calling my family members also

Why do you think WE are calling you?

This is a discussion forum where one can report or describe suspicious or unknown phone calls, but reporting them here does not stop the calling.  YOU have to take action to do that!  (google is your friend).  Consider buying a call blocker from your favorite store if nothing else works.
http://gg.gg/blockers

Now this is a new one.  It comes up as only Illinois.  Call, answer, no one is there.
I have to think that this is connected to similar calls from 7733124951 and
3124730911  I don't even get a chance to tell them to stop calling because no one is ever there.

Is there any advice about calling the number back or not?  I certainly don't want to encourage them.

I wouldn't call back it only confirms your number they will call even more .