AT&T refuses to provide PTR records?

Anyone familiar with AT&T's policies on PTR records for their customer-assigned address space? We have a customer whose website we host that has their own in-house mail server that they run off of their AT&T internet connection at their office. We handle the DNS for their domain name. AT&T is refusing to set up PTR records for them because they're not handling DNS for the domain name. Is this normal? I haven't dug through the ARIN agreements but I thought it was required to provide reverse DNS on your allocations. Thanks, David