Simply pay your phone co. for caller ID, and don't pick up for any Caller ID you don't know or expect. Let 'um suffer.

I got a call from this number, but didn't answer. The strange thing is that after I block it on my iPhone, another call will come in from a different area code. All of the numbers have a different area code, but are followed by 555-01xx. So there's a hundred different possible combinations of xx. And, there are hundreds of area codes. I've been blocking 3 or 4 of these per day for the last. At this rate I'll be blocking calls for years. How can this be stopped?

get caller ID and don't pickup unless you know the caller's ID

They can fake any number or name they want. Just don't pick up any CALLER ID you don't know or expect. Simple. They will go away.

how do you stop calls that show your # on the I.D.