How do I get reimbursed for unauthorized app charges on my Apple Account?

Re: Apple isn’t Reimbursing me: I have been charged for apps that I don’t use.

If this happened after free trials:

A free trial needs to be cancelled at least 24 hours before it expires, if you do not want to be charged for the following subscription period.

Else: Seems you may have settings in place that allow unauthorised downloads ?

Eg: You can: Require a password for purchases in the App Store and other Apple services - Apple Support

If using iPhone, you may want to check or set restrictions:

Change settings and restrictions in the App Store on iPhone - Apple Support

If using a Mac you can:

Manage Media & Purchases settings for your Apple Account on Mac - Apple Support

______________________________________________________________________

Re: "Apple refuses to reimburse me or even provide any support or assistance "

Were the apps Apple products, or does a vendor or app developer have your money ?

More info: About purchases not billed through the App Store or Apple In-App Purchase - Apple Support

Eg" says:

"If you paid for an app, a purchase within an app, or a subscription outside of Apple’s ecosystem, contact the developer for billing support or a refund. Apple is unable to provide support for these purchases".

There's much more info. in the above linked article.

________________________________________________________________

Also: A well-respected community member has created a useful "User Tip" that may be helpful to you in the situation: See: Billed, but you didn’t buy? - Apple Community