If you have deleted a single file and wish to retrieve it, it is possible as long as you are using an HTML5 compatible browser (IE 10+, Firefox, Chrome, or Safari). When you have deleted the file, you will see the option to undo this action pop up in a blue bar at the bottom of the screen.
If you do not have the option on your browser or you have refreshed the browser since you clicked delete then you will need to contact the Huddle Help team. It is likely that we will be able to retrieve your files but the sooner you tell us the better! Please submit a ticket from the support portal or email firstname.lastname@example.org and let them know as much information as possible. You will need to include information such as, the name of the file(s), the name of the workspace that they were from, and who deleted the files and when.