If on contract you can look in your MyO2
http://www.o2.co.uk/myo2 but if PAYG you can either look in your phones call log or request a SAR
http://www.o2.co.uk/help/safety-and-security/how-to-get-a-copy-of-the-information-we-store-about-you
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.
Please select the post that helped you best and mark as the solution. This helps other members in resolving their issues faster. Thank you.