Recovering Deleted Files

First of all, you should stop using the partitions where the files were removed because you may overwrite the sections of the disk where the removed files were. If that happens (or happened) all hopes of recovery are lost. You can use a Live system.

Install and execute the "PhotoRec" program. It is in the "testdisk" package in Debian and derivatives (and, yes, you can install a program on a Live system). See http://www.cgsecurity.org/wiki/PhotoRec_Step_By_Step for step-by-step instructions. Notice that the file names and their paths are lost. The real work therefore comes after: finding the files you care about among all those that were recovered. See http://www.cgsecurity.org/wiki/After_Using_PhotoRec for a few useful scripts.