Cancel Sky Entertainment Subscription

I subscribed to o2 sky entertainment. Sky Entertainment were not able to verify my identity online and so I could use their services. However, I have been charged for the sky  entertainment in my current bill for services that I were not able access as the registration at Sky entertainment was incomplete. If possible, i would like to ask for a refund of this amount charges in my monthly invoice. Secondly, I would like to cancel my o2 sky entertainment subscription.