Go to your O2 account and select 'Membership and Subscriptions' Scroll down to 'Cancel Subscription'
Contact the business and say you want to cancel the contract because you're still in the cooling-off period. You'll probably need to give them details such as your account reference number - check any documents or emails you have from the company.
O2 end of contract tariff options If you happen to be out of contract with O2 already, it will send you an annual reminder that you're still paying for an old tariff. In these notifications, O2 will offer you a selection of new plans that you could move onto once your fixed-term is finished.
O2 end of contract tariff options If you happen to be out of contract with O2 already, it will send you an annual reminder that you're still paying for an old tariff. In these notifications, O2 will offer you a selection of new plans that you could move onto once your fixed-term is finished.