I can't remember charges for local exchanges (same area code), but I only remember as far back as the late 80s. It was something like 10 cents a minute. I remember all the adds about "friends and family" special rates/etc. Metering on voice calls persisted into the 2000s.

But the calls were very brief (if they did pick up) unless he got a "hit". So thousands of calls could have no charge

Or maybe he spliced into his neighbors line :-)