I clicked on the small shopping cart next to a piece of footage to see what the price was and it automatically bought it!! It wasn't the right piece of footage that I want to buy. How do I get a refund or credit?
As you mentioned that you have accidentally licensed the video footage, I would request you to Contact Customer Care for the refund requests.
Please see Contact Support FAQ: Unable to reach support through the "Contact US" link in case you are unable to reach the support.