OS X Mountain Lion :: Startup Disk Not There When Reinstalling (Early 2013 MBP Retina)

I had reinstalled the OSX on my MBP a few times so I am not unfamiliar with the process of rebooting from the boot menu, formatting via the disk utility and then reinstalling either via a backup or from the internet backup (as the retina does not have a dvd drive). Doing it this time and I did nothing different, however upon entering the disk utility screen, the main disk image simply wasn't there. I was conducting a reinstall of OSX from the internet and had already downloaded the new software, as you have to do when installing from the internet.

I then came to the disk utility screen, ready to reformat the hard drive and it simply wasn't there at all. The only image there was the one I had just downloaded ready to install. Thinking this extremely strange, I reboot the computer and it takes ages, then comes to a screen with a continually flashing folder symbol with a question mark in it. I have left it like this for 30 mins with no change. So now, I cannot boot normally, and I cannot reinstall a downloaded image on the main SSD because it is not showing at all in the disk utility. I have plugged in an external hard drive and am currently installing a new image on this to try to check where the main hard drive is once it is up and running. As mentioned, it is an early 2013 MBP retina, the warranty is up so cannot take it back to apple.

Info:
MacBook Pro with Retina display