My content was unexpectingly erased when I was looking at other themes.

I had a presentation almost finished. and when I went to look at other theme colorways it deleted all my content and reverted to the blank theme.

Can you help revert it to the previous version?

My URL is below..

http://prezi.com/hmaf8wnss-0a/?utm_campaign=share&utm_medium=copy&rc=ex0share