Did you purchase your Vega64 directly from AMD or is the manufacturer someone other then AMD?
If you didn't purchase your Vega64 directly from AMD then you need to open a Warranty with the manufacturer of the Vega64 (MSI, ASUS, GIGABYTE, XFX, SAPPHIRE, etc).
Some manufacturers like Sapphire Warranty for RMA purposes requires the User to return the Hardware through the Retailer who is the one that decides whether to RMA the hardware or replace it or refund a Pro rata cash refund.
