Pretty sure all ROG motherboards have a socketed BIOS chip. You should be able to replace it for as little as $10, plenty on ebay. Some come preinstalled with the correct BIOS, so you won't have to flash it. Find the correct chip which is compatible with your specific model of board.
That's probably the worst case scenario, someone else will probably have another idea.
I can't be sure that it will work, but for $10 it could be worth a punt. Someone else will contribute and give a better idea. I can't understand why it wouldn't let you flash it with the retail. Maybe try flashing it again.
This is the board. It looks exactly like the retail version.. apart from a few physical differences. It's originally from the Asus CG8265 desktop PC... I think... lol
As for the link.. I can't find anything about this OEM board. Neither can I find much of anything on the Asus CG8265 desktop PC.
Bought it from a seller named "Better online choice"
It's very frustrating though because I Emailed them about it and a guy replied to my first Email. I then answered his reply and a second guy replied to my second Email... The thing is the second guy had no idea what the first Email was about.. Terrible customer service.
D; I'm sure you could send it back. It's the 7 day consumer e-commerce law thingy, that the company needs to abide by, surely?
If you are dissatisfied with something you have bought online, you should be able to send it back within 7 days. At least, that's how the law goes in the UK.
30days for Amazon.....(have a quick google if that applies to their affiliate too, or just go into your account and see if you can just process a return as normal)
If you're dissatisfied with the motherboard, I think you're protected by consumer rights.
At the end of the day, it doesn't do what you expected it to do. However they might have sold it to you. Though, they told you it was OEM, you would still expect it to have the correct BIOS.