Theme purchases from the Shopify Theme Store are final sale and non-refundable. When you purchase a theme, you immediately gain full access to the theme's source code, and Shopify can't revoke that access after purchase.
Before purchasing a theme, consider the following:
Try before you buy: You can try any theme for free in your store before purchasing. Use this to verify that the theme works for your needs.
Review theme documentation: Check the theme's features and requirements on its listing page before committing to a purchase.
Contact the theme developer: If you have questions about a theme's functionality, contact the developer through the theme's listing page before purchasing.
The only exception to the theme refund policy is when transferring a paid theme between stores you own, which involves a specific process managed by Shopify Support.
For more details, you can refer to Shopify’s official documentation here.