Info checking returning Amazon Japan

Bought my girlfriend a apple watch charger through Amazon Japan. But while waiting the delivery she had to get one. So after the one I bought arrived, she decided to return it.
Here's the issue:
The charger was 2.000yen
After 1 week of arrival she returned it via Yamato.
We choose returning reason: "changed my mind about this purchase".

Japan being Japan I expected them to charge the shipping fee of the return, but they also charged "Returning fee" on top of the shipping fee. Returning only 25% of the total value.

Refund subtotal ¥2,049
Shipping: -¥500
Return fees -¥1,025
Total refund ¥524

Is that normal? If I knew that I would keep it..
Should I dispute it?
That's ridiculous.

by Add0z