I managed to get a second Mobley on the $20 plan, although it was a long process.
This summer, I called and asked if it was possible. I called two or three times, maybe once a month. Eventually I got a rep who said yes :-).
But of course it turned out that I didn't really end up with the $20 unlimited plan on the second Mobley.
However, since the rep had said that I could have it, subsequent reps put me on a request waiting list.
In the meanwhile, I called in every month, and they credited me for the overages. They said there was only one rep in all of AT&T processing the waiting list, so it took a while.
But after 6 months, I now have the unlimited plan on both Mobleys!
So it seems they are still offering this plan, in a very limited way, and one that depends a lot on luck. I'm offering this story in case it helps somebody.
