on 25-08-2020 16:32
You can cancel any O2 Extra from your O2 App, which you can download from your device App store. The App is called My O2, once you login have a look for extras and you will be able to cancel.
Hope this helps.
on 25-08-2020 16:55
Tap or click the + sign to expand the options.
OnePlus 6 (O2 & Sfr), Z3 Tablet (Three UK), iPhone 8+ (EE)