If you're already an admin for the zone in question, then the proper way to get that information is to log on to the DNS server or DNS control console and read it right from there. If you're not an admin for the zone, you're not supposed to have that information. Note that the person you are talking to on the phone is almost certainly not a DNS zone admin, so they also should not have that information. If they somehow did have it, they definitely shouldn't give it out over the phone. This is for your protection.

DNS zone information is sensitive. Many years ago it was possible for anyone to query a DNS server and literally get back all the records at once, but that was a security issue. Now you have to be an admin for the zone to get that info.