Data recovery of hard disk.

We need someone to recover data from a hard disk that seems like something is wrong with it. The computer reads the hard disk but you can't see any folders nor any files and also it says that the hard disk is almost empty. It's a 750 GB Hard disk but none of the space is used. We did a chkdsk and should've helped but nothing. Now we need someone to help us get the data back especially the Quickbooks POS Data. That's the most important one. This would need to be done via teamviewer. Thank you very much!