Good Morning Steve1308,
Thanks for your post on our Community Forums and a very warm welcome to you!
Sorry to see you've been having issues with the device management on the TV Go account
Can you tell me if you've been able to simply try watching content on the device you're seeking to register?
You may be able to watch the content on the device and then replace one of the devices you wish to remove or any duplicated devices that are showing on your account
Kindest regards,
David_Bn