This is a user to user forum where we help forum members with advice and technical help.
You should contact Gigabyte U.S.A. support directly to see if they can ship you a replacement I/O shield.
You probably already have some of the following information:
Contact information: GIGABYTE - About GIGABYTE - Contact Us
End User RMA Service
Customer Care : rma_index
Motherboard Service Center
GIGABYTE USA Branch
Address: 17358 Railroad Street City of Industry, CA 91748
TEL: 1-626-854-9338 Option 4