redirect url after processing card details

Hi there, the module seems to work well. It processes the card details fine, and when I go into real control the transaction shows up. The issue I have is what url to redirect to after the details are processed? Realex needs the return url details so they can link back to the site. For my site I'd like the suer to be brought back to the orders complete page. At the moment the order is not getting updated even if it goes through. I tried linking back to http://www.salonsaversonline.ie/cart/checkout/complete but that doesn't seem to work. I've attached a screenshot of the error I get.

Any ideas?

Thanks,

Steve