I had a different issue. My upgrade was available on a different line. Apparently when you upgrade it immediately burns the sim card of the device and there's nothing you can do about it. So, lucky me got to purchase a second sim card before I ever touched the phone @ $20. Super frustrating.
i did the same thing but i didn't need to pay 20 bucks. they did it over the phone. it took a while but it got done.