one more thing, is it possible that the white ones are White Rocks or more likely a white jersey giant and your black ones could be black jersy's and possibly a black star?
White jersey from feathersite.com
Added: I looked it up, here is the list of possible chickens they should have sent you.
This is taken from their brown egg asst.
Note the ones in bold:
Black Australorps;
Lt. Brahmas;
Dark Cornish;
Black and White Giants;
Buff and White Orpingtons;
New Hampshire,
Rhode Island Reds,
Barred, White, Partridge, Buff Rocks;
Deleware,
Sussex,
Turkens;
White, Silver Laced, & Columbian Wyandottes,
" Red Star and
Black Star.
So maybe you still got what you wanted.
With that list, maybe people can match your breeds easier.
GL
Added, but that doesnt account for the hamburgs, so I dont know.