Please check against the following two items:

1. [Merchant refund number (out_refund_no)] is reused, that is, the merchant refund number has been used, and a new "merchant refund number" can solve the problem.

2. The same [WeChat order number] or [merchant order number] uses a different "merchant refund number" in the refund. In this case, the "merchant refund number" used in the first refund is needed.