Hey @Add_34550 , Welcome to the 3Community 🙂
I'd love to help you here. Firstly I would recommend check the charges on My3 by going to My3 Account -> Allowance -> View Detailed Usage. If the charges are for usage outside of your allowances, eg calls to other networks not included in your allowances, then these charges would be valid and wouldn't be returned to the account.
If these charges are incorrect and you would like me to check these for you pop back to us here on PM along with your full name, mobile number, address and date of birth and I can check the account here for you.
