check - is there a "trash" folder or similar?
if not, you're going to have to call them and see if they can undelete (unlikely as it will be stored "cloudy" ) or else retrieve from a backup
I haven't found one in my transfer client (Filezilla) as i suspect it simply sends a bit command to whatever operates on the server.
Yes, I would expect the server has it's own backups but I don't have access that I know off through my transfer program. Nor a ready 800 phone number to get access to the server last backup.