First off, you need to call customer service back and get a detail on where these charges come from. That will probably answer your main question.
Keep in mind you're not being charged for "Internet Use" per se - what they're billing for is any data that crosses their network into your phone. So if you were using Medianet for weather reports or checking e-mail, that starts the kilobytes running. You might find it worthwhile to pay for a more expensive Medianet plan which will buy more kilobytes for you and save you the charges for extra usage.
Let's put it this way - I'm also a Cingular user. I shaved $40 off my monthly bill by increasing my Medianet plan from $10 to $20. Even if you find it easier to cut back on Medianet (not me!) you'll at least know how to control your charges.
I have a Sony Ericsson Z520a. My service is with Cingular. I just received my bill from December and have a $24.00 internet charge that I did not create. When I called Cingular to ask about the charge, they told me that the SIM card to my phone is unique and that no one but myself or someone on my phone could create these charges. Is that true? How is it possible for these charges to exist if I do not do it? I have only been to the internet to download one song. There are charges throughout the month of December 24/7. Can anyone help?
Thanks.

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