See the Apple Support article(s) below. Link to contact Apple Support in the article.
Normally, all sales are considered final, but you can ask for a refund. See the articles below for instructions on filing for a refund.
If you have received a confirmation email, click the Report a problem link at the bottom.
Request a refund for apps or content that you bought from Apple *
How long refunds from the App Store or other Apple services take. *