Simple Product Attribute

Hi there,
I am trying to add size attributes as a simple dropdown menu to a clothing range.
I have created the attribute and added it to the product, ticking visible on product page.
It was only appearing as a list of words in the Addition Information box so I installed a plugin to help (woo commerce show attributes)
However, it appears as a list of words, now under the short description/above the add to basket, still not as a drop down menu.

The page I need help with: [log in to see the link]