Simple exit to "downloading don't turn off target " downloading mode
I enquired and found some answers to this problem.  

1) If you press the exit button in the recovery menu, the phone will reboot and regular app screen should be seen.

2) as answered earlier wipe cache does not delete user data, (only system cache files are deleted)

3) to exit the download mode (when not flashing anything to the device) is to either pull the battery or long press the power button (which simulates a battery pull).

Anyways what I did was take the device to support center and they told that IC power chip needs to be changed and was charged abt 27$ or so. No data was deleted at all.

Thanks to everyone who helped and especially Golfdriver97.