Yeah, just like with the original purchase. They made money on that too, but returned the full amount, including their margin. Amazon loses money on this compensation. They don’t sell stuff with a 10x margin.
Step 1: OP bought a video for $5.99 Step 2: he gets a refund + $5 gift card Step 3: OP can buy a video for $10.99 or whatever else he wants for $10.99
Ultimately, OP wins a $5 gift card and saw a free movie.