Go to your O2 account and select 'Membership and Subscriptions' Scroll down to 'Cancel Subscription'
For athletes who purchased a training plan or adaptive training subscription via the App Store or Google Play, the ability to cancel your subscription or request a refund must be done in the app store.
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.
Almost all providers require 30 days' notice if you wish to leave.