Static IP Allocation /27 - updating whois

I currently have a /27 from AT&T, and I would like to update the related entities section when doing a whois (ARIN) to show that this /27 has been allocated to us. The challenge I'm having is that we have a partner we do business with, and their security team won't begin the process of whitelisting traffic from us until they can query whois to see the /27. Once they can verify this information, we can start the process of whitelisting traffic.

I'm not having luck with the standard AT&T support.

Rob