Cannot change theme

Hi. I downloaded a theme from hitskin.com and installed it, but i wanted the old one back. Everytime i change to the old one nothing happens. It change on the prewiev screen. but if i go to the site og refresh, its back to the old. The only ting changed is the icons and top picture..
Help?

Solved:
I randomly came over it on hitskin.com and installed it from there =)