It’s an old scam with a slight twist: lottery scammers based in Jamaica are using threats of physical violence to get victims to wire money.
Usually if you ignore a scam, that’s the end of it. Apparently this group takes it really personally, though; if a potential victim refuses to bite, they make threats. At that point, I suppose the whole “you won the lottery” angle is abandoned and it just becomes pure extortion.
Sometimes I make really general statements, and I’m going to do it again here: unless you personally know someone who lives in Jamaica or own/work for a company that does business in the country, don’t even answer phone calls from the 876 area code. There are exactly zero good reasons you should be getting out-of-the-blue phone calls from random people in Jamaica. The St. Louis BBB has some additional information about this scam.