Amazon Refunds for Export Fee Reduced

Today we received an email from Amazon US which is about an item refund. But we never applied for refund from Amazon US, what’s going on ? After we read the email, we knew the refund reason is because “Export fee reduced”. Even the refund amount is very small, but we think that it is interesting, also, it makes us more trust Amazon.

The following is the email content:

Hello,

We're writing to let you know we processed your refund of $0.19 for your Order xxx-xxxxxxx from Mobile Dist.
This refund is for the following item(s):
Item: T-Mobile T-Mobile (AC-1900) By ASUS Wireless-AC1900 Dual-Band Gigabit Router, AiProtection with Trend Micro for Complete Network Security (Certified R
Quantity: 1
ASIN: B075GYWPCJ

Reason for refund: Export fee reduced
Here's the breakdown of your refund for this item:
Import Fee Deposit Refund: $0.19

We'll apply your refund to the following payment method(s):
Visa Credit Card: $0.19
Visa Credit Card: $0.19

We've processed a refund for the above order in the amount of $0.19. In most cases, once a refund has been submitted, the issuing bank will post it to your account within 3-5 business days when issued to a credit card. Refunds issued to a bank account or pin-less debit typically take 10 business days to reflect on the account balance. This time frame may vary from one financial institution to another.

Have questions about our refund policy?
Visit our Help section for more information:
http://www.amazon.com/refunds

We look forward to seeing you again soon.
Sincerely,
Amazon.com
We're Building Earth's Most Customer-Centric Company
http://www.amazon.com