I got an email receipt for an app I didn’t purchase.
The invoice is from Apple?
Click Report a problem.
If the invoice is not from Apple, was the money deducted by a stranger?
Contact your bank, they can find out who (name, address & account number) has collected the amount from your bank account, and when.
Depending on your bank, they can collect the amount back within 30 days.
Ask the bank to block your card, and ask a new card.
Also report to the police.
an app purchase to my credit card and my Apple ID?
See the following Apple articles:
If you think your Apple ID has been compromised
If you think your Apple ID has been compromised - Apple Support
Personal Safety User Guide
Personal Safety User Guide – Apple Support (UK)
Security and your Apple ID
Security and your Apple ID - Apple Support
Don't jailbroken your iPhone.