Have you had any luck with this? I've had the same problem since switching to FiOS, and haven't been able to get anything but a canned response. I can watch a small selection of channels, but not all of the ones that I subscribe to. It shows the message "Connect to your in home FiOS WiFi network for more channels!" which I am, since it is a WiFi only iPad.
It's pretty frustrating since I was able watch on-demand movies on my iPad with the Xfinity app with zero troubleshooting, and this one only let's you watch live TV and it doesn't even work correctly. I'm beginning to regret switching from Comcast.