How do I request refund for an unintended app subscription transaction not showing on App Store?

I had money deducted from my account through Apple media services against an app subscription that i had no intention to pay for. I immediately cancelled the subscription. The app refund team is saying App store will handles all the refund, but on app store the transaction is not even showing. The report a problem page of yours doesnt have any option to address this issue either. I need to know what's going on with the transaction.

[Re-Titled by Moderator]