Unable to retrieve a saved Prezi

I am unable to retrieve a Prezi that was saved in the past to use for training. The Prezi is gone and all that remains is an untitled prezi that has only 2 slides completed. How can we retrieve the full completed presentation? The product is Prezi for non-profits, the operating system is Windows XP and the browser is Explorer. The account URL is http://prezi.com/user/b3wtdwg0lbxh/