Came across this link on Washington Post. Any truth to the claim in the question?

http://www.washingtonpost.com/wp-dyn/content/article ... »

Q: I've had AT&T's unlimited-data plan since 2007, but the carrier cut off my service this weekend.

A: Yes, you've read a version of this question before.

In a July Help File column, I addressed a query from a reader who was charged an overage fee on an allegedly unlimited, data-only wireless plan. At the time, AT&T said this and other customers had altered their accounts in ways that kept them from continuing their service.

This time around, Harold Hamblet of Savannah, N.Y., hadn't changed anything since renewing his service in 2009. But he was still met with a demand to sign up for a new, $60 DataConnect plan with a 5-gigabyte cap or close his account.

AT&T spokeswoman Jennifer Clark said that didn't matter. She wrote that the carrier, having ended support for the unlimited option, no longer lets longtime subcribers keep a grandfathered status. They need to switch to the same plan as a new subscriber.

The Dallas-based firm didn't mention any such impending change in July. Clark's explanation: "Your inquiry was in July - before we enacted this policy and began proactively communicating to customers in August to educate them of their two options."