Im not sure if this is something you can help with or its something with the store Im using (WP-Commerce).
Im using the eway gateway plugin and I cant get the site to show a payment declined message, it just refreshes the page. I've looked at the WP Commerce site and there are people asking about this (from 2011) but no one has responded.
Is this something you can assist with or at least confirm that the plugin handles the error messages. I would be willing to pay for assistance to fix this.