In the content section within a product you will see a section called Refund Period.
Here you have control over two things.
1) How many days after purchase a customer can request an automatic refund without having to communicate with you at all.
2) Wether or not they can download files during that refund period
On the users end, they can view content and listen to any MP3 or MP4 files from their content screen in their account. but If you have restricted downloads it won't give them that option til after the refund period.
If they want to waive the right to the refund and get their download or if they want a refund for the purchase they can do so by going to their account and managing their purchases. On that screen they will see the refund option (Arrow #1). If they choose to waive their refund they can simply hit the green button and then the content button to the right (arrow #2) to view the content.