Undo bulk import and deletion

I downloaded my contacts to .csv last night. Made some changes to a single column and uploaded the new file, resulting in several hundred new contacts. I then tried to correct it by uploading the exact file that I had downloaded, hoping it would put everything back together, which it did not. To make things worse, I then deleted the 2 files that I had uploaded and have now lost 99% of my contacts. Is there a way to restore things to the way they were before I uploaded anything?