Double check and see what your myAT&T account shows for a new line with a phone number that you don't already use.What does it take to get a damn watch activated. Mine has been stuck on activating for over 13 hours and no one can seem to get it activated. I have turned on and off both phone and watch several times. We have even went as far as removing the watch from my account and re adding it. What's hilarious is when I go into my account under the ATT Unlimited Wearables plan it shows up as an LG 440G.
I have called ATT several times and am amazed at how ill equipped ATT is. I have talked to 15 CSR's today and still have not gotten my issue resolved. At this point I think I just might jet over to Tmobile and return the watch back to ATT.
I would suggest that you unpair, deleting the plan from the device along the way and then power cycle both devices and try activating again.
If that does not get you any progress then let us know what iPhone and plan you have on your account. For example do you have an individual line or multiple lines?
And yet again, don't worry about what device is listed on myAT&T it is the plan that matters. You should expect a random device name to be listed until your watch is actually connected to the cellular network. It will knock the network up side the head and say I am an Apple Watch.
Dave