Even though order is complete, from Billing => Transactions List you might not see any transaction data related to the order.
If you go to admin/configgeneral.php, there is an option Auto Redirect on Checkout. Is the option ‘Automatically forward the user to the payment gateway’ selected? Then during the order, customer must have gone through the payment gateway module code. Even then why no transaction id and other data?
Go to ‘Manage Orders’ from admin side. Is the payment status of the order is complete? Is your refund failing for the invoice of the order? Are you getting the error ‘The refund attempt has failed. Please check the Gateway Log for more information’ when you try to refund?
It’s happening because the customer have some credit balance. The amount is deducted from that for the order.
If you are a developer and would like to test a refund for the payment gateway,you can simply reset the credit balance as zero for the customer.
Then place a new order and refund for that order will work.
To know credit balance of a customer with id [x],
go to the page clientssummary.php?userid=[x]
and search for Credit Balance.