Deleted BootCamp Partition into Unallocated Space, how to get it back?

So I'm trying to install Windows 8 onto my Macbook Pro 15" Retina, Haswell and I was following on of the poster's instructions.

The steps went along like this:

"1. setup and update mavericks and reboot

2. open boot camp assistant and only check the lower 2 options

3. insert a usb flash drive (for boot camp driver install

4. plug in a usg dvd drive with a retail copy of windows 8 or 8 professional

5 select how big you want your partition. I recommend at least 80gb but just a suggestion based on needs.

6 when its done creating the windows boot camp usb eject the usb drive before you allow it to restart to install windows.

7. when it is at the install screen you will see a message saying that partition 0s4 is unable to install windows. highlight that windows partition and click delete then highlight it and select format.

8 click next to proceed with install

9 when in win 8 run the boot camp installer and all windows 8 updates. restart

10 go to the windows store and select the windows 8.1 update and click install

11 after a restart you are at 8.1 Done. Enjoy."

So I did step 7 and I was unable to hit format and it said from BOOTCAMP to Unallocated Space. I quit out of the installation process since there was nothing else that I could do. I go back to Bootcamp hoping to remove the parition and it's not there...instead, it gave me to the option to add a partition. When I click it to see what it is, my Macbook now has only 350GB left..it originally has 500GB. I'd tried to get into Disk Utility but the HD drive doesn't show on the sidetabs...can anyone please tell me how to recover my 150GB..? Thank you!