Sorry to hear that TV Anywhere is not working on your iPad.
If you sign into your account, under My Profile click on Device Settings. You should see that 2 slots have been taken and they are called the same. If this is the same device then it will cause conflicting information. As you have one device change available, remove both registrations just in case and go back onto the iPad. Open TV Anywhere and start streaming a channel as this will prompt you to register the device again. Hopefully this will then work for you.