Ok, did you send any iMessages on the days you got charged?
From memory any time you turn your phone on/off it connects to a data network for a fraction of a second, which would be enough to register a data charge.
The best time to contact customer service is between 8 and 8:30am.
You definitely need to speak to them if you think the charge is an error.
Please note, this is not customer services and we cannot access your account. Do not publish personal details (email, phone number, bank account).
Link to our guide on how to contact them can be found here
