I do have 4G selected atm, didn't notice how much it used when I had 3G selected.
I don't know if this is an issue or if this is normal. Will it help if I post a screenshot of it, showing how much it used in X hours?
If so, let me know if to charge the battery, or leave the phone unused for a while, before taking the screenshot (so you will be able to compare the info with yours).