Since last month, I've been using a PAYG Nokia 2600 phone, after returning my iPhone 3G to AT&T. I bought some minutes when I purchased it, but ever since then, have not had to buy any minutes. At first, I thought I was just given some "freebies" for being an existing AT&T customer. (I used my AT&T SIM, just like the box suggested.) But, a few days later, I realized nothing was being charged. So, I began to get suspicious, and I noticed my 5,000 rollover minutes were being consumed by my data usage and texting charges. Yet, even until two weeks ago, nothing was added onto my AT&T bill. Tonight, I logged onto my AT&T account, and my bill is over $500. I go to change my features back to the Data and Messaging Unlimited package, and it tells me I can't do that with the phone I have, but I can reverse it if I talk to AT&T's Customer Service. (One of the options to select from before finalizing the feature is to backtrack the payments to the last bill to reverse and overusage. I need to do this, but I can't!) Why is my PAYG charging my AT&T account?