To keep your Apple ID account secure, 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
See who has access to your device or accounts
See who has access to your iPhone or iPad – Apple Support (UK)
Delete suspicious content from your devices
Delete suspicious content from your devices – Apple Support (UK)
Personal Safety User Guide
Personal Safety User Guide – Apple Support (UK)
Never jailbroken your iPhone.
Change your Apple ID password.
Create a strong password for your Apple ID, It is best if your password consists of eight or more characters and include upper and lowercase letters, and at least one number. You can also add extra characters and punctuation marks to make your password even stronger.
Never provide your password, passcode, security questions, verification codes, recovery key or any other account security details to anyone else. Apple will never ask you for this information.
Then see this Apple article: What to do after you change your Apple ID or password
What to do after you change your Apple ID or password - Apple Support
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You can try to -> Request a refund for apps or content that you bought from Apple.
Request a refund for apps or content you've bought from Apple – Apple Support (UK)
If you have requested a refund, you must wait until Apple has approved. Then you will receive a message from Apple.
Refunds are not guaranteed. For more information, see the Terms & Conditions.
