Looking at your screen shots the url shows that your are still on the Worldpay.com websites (https://secure-test/worldpay.com...) and not on your UC site.
Yes correct but what does that mean? The shopper goes to the Worldpay site for the card verification and is then returned to the UC site. So this 'order complete' page' is the result of a successful transaction. I think this page is http://www.example.com/cart/worldpay/complete but yes for some reason the URL still shows worldpay. I will check but I think this is normal / what is supposed to happen
Thanks.