Why the storage space is not freed even after I have deleted the files?

iZip, iTransfer and Power PDF now support the "Recycle Bin" feature when files are deleted. The deleted files can be recovered in the Files app. That's why the deleted files are not immediately removed from your device. They will be removed in 30 day after deletion. To immediately remove these files from your device, please open Files app, go to Recently Deleted. Select all files and delete.