Guest Checkout - not being redirected to payment

-- url of the page with the problem -- : www.epma.com/publications
-- HikaShop version -- : 2.6.0
-- Joomla version -- : 2.5.28
-- PHP version -- : 5.4
-- Browser(s) name and version -- : Firefox

I've got a problem with the Guest Checkout, and Create an Account checkout.
When a user checks out via one of these methods, they will not be redirected to the payment gateway (SagePay) [1] and instead will just see a screen that says "Thanks for your purchase" [2].

In the back-end order screen, the Payment method field will be blank [3], and when the user is logged in via the front-end, there is a Pay Now button that doesn't go anywhere [4,5].
If I edit this as an admin [6] - changing it from 'None' to 'Sagepay', then the user can now see the payment option in the front-end [7].

Do you know why this might be happening?

I have also attached our checkout config.

Thankyou! That was it. I should have realised really as I've already done the same for the Shipping (hidden it via css)!