galaxy watch 5 lte

I purchased a galaxy 5 watch LTE from Amazon.  I've been trying for 4 days to get the cellular line activated.  (Actually, I'm on my second watch because when it couldn't be activated, I was told that the watch was defective).

So now after 2 hours on the phone with an "expert" and 2 visits to the Xfinity store, my watch still isn't activated.  The first trip to the store was a fail because the servers were down.  The second time, I was told that again they were having problems.  I was told the activation could take 1-24 hours to complete.  It's been 22 hours and no sign of activation being complete.  I don't have much faith that it will activate.  So here is my question...do you have to buy the watch from Xfinity even though they advertise that you can bring your own?   They didn't have color watch I wanted, so I chose to purchase elsewhere.  Xfinity supposedly now supports the Galaxy watch for LTE.  What is going on?