You can perform a refund for a QR transaction up to the value of the original transaction within 90 days for WeChat Pay or for up to one year for Alipay. The customer will need to show you their original transaction receipt for you to get the refund code. You can view the user guides for Alipay & WeChat Pay payments for steps on how to process a refund. You can refund any amount up to the original transaction.
Watch this short video showing how to process a refund in standalone mode.