Google Play purchase:

Go to your Google Play account: https://play.google.com/store/paymentmethods

On top of the screen, click/tap on "Order History" and find the order you want to return.

Select Request a refund.

Complete the form and note that you would like a refund.

Apple Store purchase:

Go to the apple CS center: reportaproblem.apple.com. 

Sign in with your Apple ID and password.

If you see the "Report" or "Report a Problem" button next to the item that you want to request a refund for, click it.

Follow the instructions on the page to choose the reason why you want a refund and submit your request.

If you have any further questions you can contact us here: [LINK]