I'm not sure why you would not be storing the order information in your db, and why the info would not be getting sent back to you upon checkout. If you are using the eWay xml then the values should be retained directly on the site, if you are using the remote checkout then you may need to retrieve the values from your db based on the values that are passed back.
To get at the values that are posted back to you from the gateway you would go to bindings > eCart > checkout. If you are using the local checkout you would choose local and select the appropriate gateway response from the list, if you are using the remote checkout then you would choose this and select the gateway from the list. This will give you the bindings for the info that is posted back from the gateway.
If you can please post back with a copy of your confirm page minus any of the sensitive details and I will examine it for problems on my end. If I cannot quickly find the source of the problem or do not understand the nature of the issue I will open you a ticket so that we can investigate this further and exchange some more files.