Thanks for reaching out to us on our Comcast Business Support Forums, aaeonusa!
I can help with you rDNS request. Please, send me a private message with your full name, address and, the phone number listed on your account as well as the Comcast Static IP and the domain info you need the PTR set to. To send me a message, click my name and you'll be routed to my profile. From there, you should see the option to send me a private message on the right side of the screen.