If you can, get the company name and address - my guess is, he won't give you anything, because he's trying to scam you. Tell him that you're recording all calls - most scammers don't want to be recorded. If that doesn't faze him, you'll have to block his number(s) and let his calls go to voicemail.
An "Investegator Whitman" keeps calling from a Geogia number for a "Jessica Knight" multiple times. When told that he has the wrong for this person and to stop calling, he continues to call and askes personal information such as first and last name ... even maiden name. He has also asked the state I live in as well as if I am related to this other person. He did not name a company that he works for.
If you can, get the company name and address - my guess is, he won't give you anything, because he's trying to scam you. Tell him that you're recording all calls - most scammers don't want to be recorded. If that doesn't faze him, you'll have to block his number(s) and let his calls go to voicemail.