You can cancel a license via your control panel.

If you cancel the license on the same day of the purchase, you will receive the full amount refunded to your account balance.

PLEASE NOTE : 

This is not within 24 or 12 hours, but the same day.

If the license is purchased on 8th August at 22:00 am, you can cancel this until 8th August at 23:59 pm in order to receive the full amount refunded to your account balance.

This refund is not applicable for renewals.