Deleted files can usually be restored yourself in OneDrive and SharePoint. With version history, you can also restore an older version of a file, e.g. after accidentally overwriting it.
Restore a deleted file
Open OneDrive or the SharePoint site in the browser (via portal.office.com).
On the left, choose Recycle bin. In SharePoint, it is under Site contents › Recycle bin.
Select the file or folder and click Restore. It reappears in its original location.
Restore an older version (version history)
In the browser, File Explorer or Finder, right-click the file › Version history.
Select the version you want based on date and person.
Click Restore. The current version is kept as a separate version.
Tip: In Word, Excel and PowerPoint, you can also use File › Info › Version History.
Good to know
Deleted files usually stay in the recycle bin for 93 days.
If many files were deleted or changed at once (e.g. by malware), your entire OneDrive can be restored to an earlier point in time: Settings (gear) › Restore your OneDrive. If in doubt, contact support first.
it-tects restores files on network drives or stored locally on the device from backup. Please provide path, file name and approximate time of deletion.