Refund
I accidentally purchased an emoji app. $74!! I canceled it right away but apparently I’m still supposed to pay. How can I get a refund if that choice isn’t there in my purchase history?
iPhone 7 Plus
Strictly speaking all purchases are final (after all, you can't very well return them): please see this page for information on requesting a refund: Request a refund for an App Store or iTunes Store purchase - Apple Support
However Apple have been known to be sympathetic in cases of actual error, so it's possible that they may allow you a refund as a one-off concession: but please be aware that they are under no obligation to do so: go to iTunes Store - Contact Us - Official Apple Support
Alternatively go to the page suggested in the Help page linked to above: Report a Problem