I renewed mine in jan, emailed them to ask to cancel and they said this
Hello Scott,
Thanks for emailing us regarding your phone number 07*******.
We're sorry to learn that you want to cancel your contract with us.
Please be assured that no other UK Service Provider offers free calls to Non Geographical numbers (such as phone numbers starting with 0845) as part of the tariff allowance. We're the last Service Provider that started charging for the calls to Non Geographical numbers.
Calls to Non Geographical phone numbers will be chargeable from 28 September 2007. I've set the disconnection date on your account for 28 September 2007.
Please note that you'll not be charged any termination fee.
A final bill will be sent within 7 to 14 days of the disconnection date above. It'll include any charges or credit due on your account.
If you've any questions or if there is anything we can do to retain your valued custom, please contact us on 08706 007 102. Lines are open Monday to Saturday between 08:00am and 06:00pm and Sunday between 09:00am and 05:00pm. Calls are charged at 20p per minute from O2 pay monthly phones.
We hope that you'll consider using O2 services in the future.
Important - When you email us please provide: your date of birth, postcode and mobile number as it helps us answer your query faster.
Kind regards,