Why did Amazon give me a refund when I haven't refunded my purchase yet?

So I recently requested a refund from Amazon for an iPhone case and they emailed me today saying that I have my money back on Amazon. I had like 14 dollars, now I have 22, without returning the item yet. So my question is, do I have to return the item or do I just get my money back while I keep the item? And is Amazon going to send me some envelope to return the item in?

(OPTIONAL)
The email read:

Hello,

We're writing to let you know we processed your refund of $8.99 for your Order ___from Early shop.

This refund is for the following item(s):

Item: [LF Blue] Apple iPhone 5 Ringke SLIM LF Premium Hard Case [AT&T, Verizon, Sprint, Unlocked] - Rearth ECO Package
Quantity: 1
Reason for refund: Order cancelled

Here's the breakdown of your refund for this item:

Item Refund: $8.99

We'll apply your refund to the following payment method(s):

Gift Card: $8.99

This amount has been credited.

The amount credited to your Gift Card balance should be automatically applied to your next eligible order on our website.

Have questions about our refund policy?
Visit our Help section for more information:

http://www.amazon.com/...amazon.com/refunds" class='ext_link'>http://www.amazon.com/...om/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

Note: this e-mail was sent from a notification-only e-mail address that can't accept incoming e-mail. Please do not reply to this message.

I'd wait and see if they send anything

I would guess that they messed up and will fix it before your purchase is finalized.

Yes, you are right; we all want to send you free money. You should include your address so we can send you checks, discount coupons, and robot slaves who will go to work while you stay home and sleep in. Magic happens because you let it.