Unfortunately as this is an account issue there isn't anything we can do except advise you to call CS again.
If they are still unhelpful you can complain officially if you wish.
All details on this link
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.
Please select the post that helped you best and mark as the solution. This helps other members in resolving their issues faster. Thank you.