Unfortunately if you delete your files, they are indeed deleted. We are working on a new version which will move deleted files to the recycle bin and then automatically delete files from the recycle bin after a week.
We have already done so for web-based emails. Sorry at this time we cannot recover the files for you.
To be safer, you can also consider using DriveHQ Online Backup, which is designed for data backup purpose and it is safer. Online Backup can keep multiple versions of your files. So even if you over-write your files or delete files on your local PC, the files on our server are still safe.
