Theme Editor Problems – Please Help!

I was editing a theme in the theme editor when I accidentally removed something. So I deleted the theme from the database and my computer, re-downloaded it and installed it. Activated it and the change I had accidentally made was still there. It seems as if the theme editor keeps pulling up the files I edited and overwriting the original theme files, but I deleted it all of my computer and wordpress! I’ve even tried different computers, clearing cache, different browsers, you name it. Nothing seems to work.

Help is greatly appreciated,
Thanks!