One call, Sunday evening 8:30pm (Pacific Time) from "John" -- had a thick Indian sounding accent.

I told them not to call me and that I'd be calling the police... Hopefully that deters future calls.

It won't. What will law enforcement do to criminals overseas? Anytime you get a random call from a foreigner, regardless what it's about (especially a computer), hang up at once. He can still pass your number along for a price since you answered. Numbers featuring an absurd amount of zeros are usually bad, and often bogus tech support calls.