You need to contact Intel Customer Support. Here is a list of phone numbers: http://www.intel.com/p/en_US/support/contact/phone.
I am curious; how do you know it is a bad motherboard? What is the problem that you are seeing?
Your path forward depends upon where you bought your motherboard and how long ago . . .
1. If you bought it at retail and are still within your retailer's return window, you can return it to the retailer. You could then get a refund or exchange it for a new one (preferably a different model and / or manufacturer).
2. If you are past the return period then you will need to work directly with Intel to get a replacement board. Contact Intel technical support.
My 2 cents:
I see from your other thread that you have a DP67BG board. My experience to date with both this board and Intel Technical Support has not been very good. I think this board and the associated BIOSes are plagued with problems. For example, reading through the threads you see people having problems with Intel's implementation of PCI slots on this board. You see features, such as the Alternate front panel power LED header that won't be properly implemented until the 400 series revision of this board. Other features such as BIOS fan control is not implemented in a way that's consistent with the manual or marketing materials. In addion the BIOS is poorly documented.
And speaking of BIOS . . . look at all the issues Intel caused with the 2053 BIOS update and Nividia graphics cards. It begs the question what if any QA/QC does before releasing a new BIOS.
I myself have problems with the USB 3.0 ports freezing when used with USB 2.0 devices (except when using BIOS 1900), double POSTing when trying to enter the BIOS, and default CPU fan speeds being automatically set below the low threshold warning level.
If you are able, return the board to your place of purchase, get a refund, and look for another board that has the kinks worked out.
Based on my experiences with Intel to date, you won't find their technical support to be of much help.