You should be able to see what the charges are for on the bill, in your My o2 - either web or app @Elaine1947
See if these are of any help:
Guide: My O2 - Bills section
Guide: How do I get to the 'Download Bill' page?
Guide: Tips to avoid unexpected charges on your bill
If not, then a call to customer services are required, or you can use social media. All numbers, and links to all the platforms, are in the guide Guide: How to find help & contact O2
Please note, this is not customer services and we cannot access your account. Do not publish personal details (email, phone number, bank account).
Link to our guide on how to contact them can be found here
