I can help you to process the refund transaction in QuickBooks Online (QBO).
Several reasons could lead to a declined refund. Here are a few:
The payment method used for the original transaction is no longer valid.
There may be insufficient funds in the customer's account.
There could be a restriction on the refund amount or the transaction itself.
We'll notify you if the refund is on hold via email associated with your Merchant Service Center account. You can check it from there.
If the issue persists, I recommend contacting our Customer Support Team for further assistance. They're equipped with tools to determine the cause and fix this. It'll also allow them to submit a ticket to our engineering team to alert them about the issue if necessary.
Here's how:
Go to the (?) Help icon in the upper right-hand corner of the Dashboard.
Select Talk to a Human.
Enter a short description of your concern and press Enter.
Click I still need a human.
Select Contact Us to connect with our live support.
Choose Get a Callback.
I've also included an article to help you learn more about managing customers' payments, ensuring accurate fund receipt and tracking: QuickBooks Payments FAQ.
Be sure to keep in touch by leaving a comment below. We want to ensure this matter gets resolved. Keep safe always!