If my employer withheld taxes for DC when they should have done it for VA, how do they fix that before I have to file a DC tax return. They keep telling me that there's nothing they can do but I'm sure there's a procedure to fix it before they issue my W2. I would likt to know how it's done.

There IS a procedure to fix it, but your employer apparently does NOTY wabnt to use it.

Just have them withhold the taxes for VA, and file the DC return to recover the taxes withheld for DC.