Not Enough Storage' Pop-Up on my iPhone 4S won't go away

There are two options, 'close' and 'settings'. I tried to press them and niether of them do anything and won't go away. Now my phone is locked. I can't turn my phone off, pick up calls, or even slide to turn it on. How do I make it go away?

How to fix a broken iPhone screen?

I was at a party and dropped my phone, when I picked it up the screen was cracked and turned black, I can receive calls and texts but I can't see anything on my screen.

Transfer whatsapp and sms from IOS 7 to IOS 6 iphone 5?

I recently updated my phone to the iOS 7 beta. When i connected my phone to my itunes and tried to restore it back to 6.1.4 it worked fine, but the backup file wouldn't restore on my phone again.

I searched online and it says that my files can't be used on a lower iOS version. So basically i'm screwed!

i'm not really fussed about game data or any settings that were saved on my phone, they are all backed up. But i really want my sms, whatsapp and pictures back on my phone!

Is there any software available that will help me extract those files from my phone and put them back onto the phone again once i restore back to 6.1.4.

I really appreciate the help! Thank you

Added (1). I have a mac. So please suggest software that can be used on macs.