7 days ago I accidentally deleted a very valuable permanent file for me, I want it back.... please help me
Like @EdenWheeler mentioned above, there's no way at all to restore files that have been permanently deleted from a Dropbox account.
Dropbox Rewind and regular file restorations can only occur for files/folders that haven't been permanently deleted and which are within the file recovery window of each user.
Unfortunately, it is not possible to restore permanently deleted files on Dropbox. Once files are permanently deleted, they are removed from Dropbox servers and cannot be recovered. Dropbox keeps deleted files for a limited time in case you need to restore them, but after that period, they are gone forever. To avoid permanent deletion, it's recommended to regularly back up your files or use version history and file recovery options provided by Dropbox.
Could they use Dropbox Rewind to restore their file from an earlier time?