Refer to this page for Apple Support features ➔ Contact - Official Apple Support
If the presented options do not resolve your issue, keep experimenting with any series of selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.
This page has telephone numbers for contacting Apple for support and service ➔ Contact Apple for support and service - Apple Support
Apple offers these proactive services to prevent this kind of things from happening, and may have expected you to have been using them after the first refund request:
You can use Screen Time to prevent unintentional or unauthorized purchases from the App Store and other Apple services. —> Use Screen Time to prevent purchasing - Apple Support
Require a password for App Store and iTunes purchases
Require a password for App Store and iTunes purchases - Apple Support
Use parental controls on your child's iPhone, iPad, and iPod touch - Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support
Ask To Buy
Set up Ask to Buy - Apple Support