Mayzonne

I recorded a 25 minute segment and immediately went to the Edit drop down menu and accidently hit Undo. Doing so erased the entire file. I used the Control-Z keys to retreive it. However, I then wanted to adjust the volume prior to playback, and to move the starting point to a specific spot. When I did, the segment again was deleted. In using Control-Z again, the entire file was lost. Does the segment still exist and if so how can I retrieve it? Thank you.