Well, last week I added another line on my family plan. The store rep somehow totally messed up everything. The next day when I wasn't using the WIFI, I got the message that I wasn't subscribed to EDGE! I called customer service, and here, the data plan had been shut off of my iPhone, and mine & my dtr's text messaging packages were also removed as well. (we were two of the already existing numbers on the plan) So indeed, here I was with phone service, but it would not allow me to use the internet through EDGE at all. When I called to get it fixed, I asked how this mess up had occurred since iPhone users are REQUIRED to have a data plan to activate their phones. Plus my iPhone is on the foundation account number too. So I questioned how there was even an option to turn it off at all on the store rep's end. The rep on the phone had no real answer but restored everything. Nonetheless, for a day and a half, I was an iPhone user with no ability to access EDGE at all.
So it may have also meant that I technically wasn't being charged the data plan rate either.