You'll need to contact DLink support, ask for level 2 or higher support to see if they will exchange it. If not, then your best bet would be to sell it on eBay or Amazon and get what you can out of it and get into a Rev B version. Or get into a more recent DIR 8 series models, like a DIR-857, 827, 836L, 826L.
Rev A's did not get the IPv6 support as it followed on into Rev B and C models.
Good Luck.