1. Open the piggy bank application and click the "My" button in the lower right corner of the main interface.

2. On the My page, select the My Order option to find the order that needs a refund.

3. Click on the order that needs a refund to enter the order details page.

4. On the order details page, find the "after-sales service" option and click "Apply for a refund".

5. According to the page prompts, fill in the reasons for refund and submit the application.

6. Wait for the piggy bank customer service staff to review the refund application, and the refund amount will be returned to the piggy bank account after the approval.

7. You can choose to withdraw the refund amount to your bank account or use it to buy the fund products again.