many calls, usually ignore them but several threatening calls today. have had lots of trouble with my number as it is linked to someone before with an unsavory legal past.
Consider a call blocker, which can stop this caller from harassing you. Don't bother trying to reason with the caller, they are probably scammers who don't care that you are not "the person they're looking for."
If you don't want to spend for a call blocker, try just not answering, or picking up and hanging up immediately without saying anything or allowing the caller to leave a voice mail. Even if they leave a voice mail, just ignore it and delete it.
I also got this bogus IRS caller, except since we ignored the first call, I got a call 3 hours later chastising me for failing to respond earlier and that the penalties would be worse!