I want to cancel all bills

Depending on what that means, some ideas may be found here:

• Subscriptions and Billing - Official Apple Support

//support.apple.com/billing

•Identify legitimate emails from the iTunes Store and App Store

•Identify and report phishing emails and other suspicious messages

• If you see 'apple.com/bill' on your billing statement - Apple Support

//support.apple.com/en-us/HT201382

And some identifiable bits may apply from reference article:

Check the status of a refund for apps or content that you bought from Apple - Apple Support

• If you think your Apple ID has been compromised - Apple Support

//support.apple.com/en-us/HT204145

• Checklist: If you want to see if anyone else has access to your device or accounts - Apple Support

//support.apple.com/en-us/HT212021

Details may be useful to plot a course of action & resolve this issue.

[Edited to add second link above.]

Why do you think your iPhone was hacked?

No, if you haven't jailbroken your iPhone, it's not possible.

Check ⤵️

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 device or accounts – Apple Support (UK)

Security and your Apple ID

Security and your Apple ID - Apple Support