Given the information that:
- The charges do not show in your Purchase History
- You are not the Organizer of a Purchase Sharing plan
- You did not give your payment details to anyone else to use
That just leaves one thing and means your Credit Card has been compromised and you will need to contact the bank of that card to dispute the charges and have your account secured. Don't be surprised if they tell you to contact Apple as that is always the first step in any bank dispute. You can do that with the link below, and the purpose is for confirmation that the charges are not on your account, Apple is not going to give you any more information. After you do that then continue with your bank on step 2 of the dispute process and tell them you contacted Apple and they verified the charges were not on your account.
Contact Apple Support - Apple Support
It is the bank of your card that approves/denies a purchase, that is not something Apple or any other merchant does. The bank is responsible for refunding your money on a fraudulent purchase. I don't know the rules on banking regulations in your region, but in the US there are specific rules they must follow and if they don't you can report them to a Government Agency for consumer protections for a resolution.