You will have to call customer services on 202 to check that out but I noticed a similar issue on my account as I had fingerprint authorisation turned on for iTunes purchases
What was happening was that I pressed the home button to exit but because of fingerprint being on I was authorising purchases!
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion. This is not Customer Service so we are unable to help with account specific issues.
Please select the post that helped you best and mark as the solution. This helps other members in resolving their issues faster. Thank you.
Sorry to hear you've had unwanted charges on your bill. 
