So I just got off the phone with Nintendo. Told them I have error code 022-2812 when I try to access the eShop. Also told them Pokemon X won't work (didn't give them that error code, 002-0102). They asked for my serial number and NNID. Was told I would be contacted by a different department very soon (probably today).
My cover story is that I haven't used my 3DS in a few weeks (mostly true, since I've been offline except one wondertrade). Booted up today to buy from eShop and got the error.
(I also own a Wii U, I haven't tested to see if that works. I have 2 NNIDs on there, one I share with my 3DS)
I'll edit and update this comment as I receive more information from the big N themselves.