If you really want to test unlimited claims, install an app like MFRadio (
MFRadio - mobile streaming radio) or radioBee, find a working radio station and just let that puppy stream radio all day long, day after day.
You could use 30mb an hour more or less doing that, I did a blog writeup on a S60 and used about 80mb data for a 2 hour set I listened to one day...