@Anonymous You don't get charged for going over on data, it just stops working.
You can see the charges you have incurred in your MyO2
http://www.o2.co.uk/myo2We can't see your bills from here so if you are still unsure, please call CS
http://www.o2.co.uk/contactus
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion.
This is not Customer Service so we are unable to help with account specific issues.Currently using:
Pixel 7a (O2 & Lyca), One Plus 6 (Sfr), iPhone 12 Pro Max (Vodafone)