years back,,, I kept getting calls from a debt collector.
apparently a typo, or an intentional lie, somebody gave my phone number as 'contact' - which I had for ~15 years, at the time - so it was not a number re-assignment issue....
I politely told them I had never done business with, never crossed the threshold of the 'offended' business. they refused to give up. so I contacted the local police department. they made a call inquiring for the source of their "information" and suddenly the debt collectors decided to give up....
at least in my jurisdiction, the police will consider issues of "harassment"
a lawyer may also work - but that is more expensive than a visit to the local cop shop....