I am afraid that someone may have given you some bad information.
A full system recovery is designed to put the system back to an "out of the box" state. That is its purpose. As part of the process, the hard drive is formatted effectively wiping it clean before reinstalling the OS. I know of no means to undo this proceedure as after a format there is nothing on the drive to "roll back" to.
You might try Recova
by Piriform to see if you can recover your files but the chances of doing so, unfortunately, are minimal as the sectors may have been overwritten with new data. It might be worth a shot though.
For future reference, always back up your data on a routine basis. If your hard drive were to fail suddenly, which they often do, You would be in the same predicament.
Also, you might want to take the time to make a set of recovery DVD's for that exact reason.
If the system is an HP/Compaq you want to use the DVD+R media the -R disks will not work.
I found that out the hard way.