The first step might be to add a default subject, including the order reference, here.
Aside that, it could recommend contacting Live Support.
Ideally, instead of showing this message, Live Support could automatically be connected (at least the first time this page loads) with a default message from the user; something like "Order OUY0RA did not succeed the first time." - so that agent knows to help this person. This behaviour could be dependent on the reason the transaction has failed.