The only case in which you can apply for a refund is when lag (or other system related issues) may cause you to accidentally purchase the same product twice (i.e. one right after the other).
In such cases, please visit the support page and open a ticket titled “Double Purchase” and add your full avatar name.
In the ticket you must copy/paste the 2 transactions from your transaction history. Make sure it contains the transaction number and details for verification.
As long as the request is submitted within 2 weeks after having purchased the product, Hart will be more than willing to refund you.