There are a few reasons why USPS might reject your refund request for a shipping label.
1. You've already shipped the package.
If you have already shipped the package and USPS has scanned the label then they will reject your attempt at a refund. Note: If you refund a label and then try to ship the package USPS will send the package back to you.
2. It has been more than 30 days
USPS does not allow refunds past 30 days from creating the label. If you know you don't need it, or you purchased the label on accident, refund it quickly.
3. Your original label is not allowed to be refunded
Some first class labels are not able to be refunded. You can read a few more of their rules here: http://pe.usps.gov/text/imm/immc9_010.htm.
Note: Refunds rejected by USPS are not up to Cratejoy, we unfortunately do not have any impact in whether your label is able to be refunded or not. It is a good idea to only purchase shipping labels when you know you will use them.