If you are sure you did not use AT&T data, you can Turn Off Data in settings. This can be a useful tool to determine when data is being used. You can for example turn off the PodCast App and observe if data is till be consumed. There are also specific setting for the Podcast App. I have Auto-Downloads turned off and Use Cellular Data turned off in the Settings - Podcast options.I did this first thing after I saw the phone switching between WiFi and the cellular data networks when I was in an area where my phone had a weak signal from a WiFi hotspot.I then went ahead and set my iTunes software on my iMAc to download the podcasts and sync them with the phone. Seems to have kept me out of trouble and busting the 2GB limit.