upgrading a tablet to a phone My son has had a tablet/data plan (tablets with data plans are registered to a phone number, that's not useable, and i guess just allows the tablet to access data) he's had it for 2 years and was recently payed off. I wanted to upgrade it to a cell phone, but every time I try to order it along with a new plan, it comes up with an unknown error “please refresh or try again later”…. And it doesn't work later, I've been trying for weeks.I'm assuming this is because of something to do with that unusable number.…Anyways, I'm not sure how to resolve the issue, if anyone is able to tell me how, it would be greatly appreciated!