A day or so, depends on how swamped they are, though your primary and secondary methods of BIOS update are the manufacturer and retailer.
Manufacturer: MSI - went through their support and they wanted me to RMA my motherboard, even though I asked for a bios update. Through reading their RMA, you are most likely getting a refurbished back and not your the board you bought. All my parts are bought new and just arrived 2 days ago, do not really want to go a refurb route.
Thank you for the response appreciate it.
I have the exact same issue with same CPU and an MSI 320M Gamer Pro board, full parts computer built (for my son) sitting on table faulty as can't flash the BIOS and will cost me a mint to return it to get the reseller to flash BIOS, or take it to a local IT shop to get ripped off to do it !!
My first AMD purchase......should have stuck with Intel.
How long did it take for them to send you a boot kit?