Recover data in a SQL Server table without backups
If you have "lost the data" because of corruption, you may be able to retrieve some of the data from nonclustered indexes. Or if the corruption is only in nonclustered indexes you may have lost nothing and can rebuild the indexes to recover the data. Search for DBCC PAGE and you may find advice from some experts on what to do.

If you have "lost the data" because someone has deleted it and you have no backup, then that data is simply gone. It doesn't exist anywhere. 

I would recommend your client make an insurance claim.