Call O2 for a refund.
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how did you check you were charged? i cant see being charged on my o2 account but want to cancel. cant seem to get through to customer service for them to cancel it. i only have a monthly bill showing on my account for my phone usage but thats its. for my extras it says i just have 29 day sleft to subscribe to the 6 month free disney+ service even though ive already subscribed but no bill showing for it. assuming it will show once the 6 months is up