If you did this properly it should work.
You can kick in the backup BIOS by shutting down the PSU from the wall, then hold down your case power button in and then turn on the power supply button, a few seconds later the board will start, shut off the power supply then. Then you can turn on the power supply again and power up the board normally and DualBIOS will kick in.
This may take a few tries to get to work but it does work!
Even if the Main BIOS is crap once the Backup BIOS kicks in it should be fine then you can reflash the Main BIOS with QFlash to the latest version.
You asked about RMA, well that is down to your Spanish office. You can contact GGTS here:
Just enter your email address and click on the language of choice.
GGTS
http://ggts.gigabyte.com/Please expect several days for a reply.