Since I purchased two of my three iPhone 5s using two friends upgrades (I only had one upgrade of four on my AT&T account), I thought I'd better ensure they all activated properly and also make sure my packages were still in place (I've got three iPhones grandfathered in on the unlimited data plan and the fourth phone @ 3GB/mo).
After checking with AT&T this evening, all is still great with my packages.. No changes to report, on purpose or by accident..
It's showing that you deactivated the old unlimited plan (for 3G) and switched to the new unlimited plan (for LTE).
I saw this when I upgraded from the 4 to the 4S. It's a little unsettling, but you still have your unlimited, it's just a different plan in their records, so they have to show when the old one was deactivated and the new one was activated.
I've had that Unlimited data program since day 1. Just gave it up to have a shared plan with the wife since she is getting her first iPhone. I was shocked to see how little data I actually used so it's no big deal for me.
When I had my 5 activated I was asked if I wanted to keep my unlimited data for my line. I said YES, of course! My son's line has 2gb but he has never even come close. When at home, we are both always on WiFi
I'm with AT&T as well, And I did not lose my grandfathered unlimited data plan after upgrading to the iPhone 5. I would give AT&T a call. I'd be pissed if I ever somehow lost my grandpa'd unlimited data plan or if I wasn't able to get it back. Call em. Let us know how it works out. G'luck