Hey, it's a really simple fix as long as your touchscreen still works.
1) Download this: http://www.mediafire.com/?5ye70x3d6vacc3s
2) Extract it to your desktop and open the folder.
3) Right Click Odin3 v3.07.exe and run as administrator
4) Boot your phone into recovery mode by holding the Power, Home, and Volume DOWN at the same time. Wait a second after the screen loads and then press up to continue at the prompt.
5) Load s3-touch-recovery.tar in the PDA folder into the PDA slot in Odin.
6) If under ID:COM something is showing up that means your phone is recognized so the last thing to do is to press start.
Note: If it doesn't recognize it under ID:COM make sure your phone is in download mode and unplug and replug the phone in again.
7) Wait for a minute or so. The program will tell you if it was successful or not and it will auto reboot the phone.
8) Lastly, boot into recovery mode by holding: Power, Home, and Volume Up for a few seconds and that should do it!
9) Enjoy the ability to flash ROMS and other firmware with a much more user friendly interface with non-functioning volume keys.