"Merchantable quality" is your claim, unless your doing something wrong. Ask for a replacement.
Any quibbles just mention "trading standards"
The White Balance dial is on top to the left of the flash hot shot and has positions for Auto, Preset and Custom white balance, as well as Color temperature i recall?
You set the dial, then press the WB centre button for the appropriate menus. Then use the 4way controller to access the WB menu/setting you want.
If thats not happening then its faulty.
Thats a cracking camera the 5D even with the basic Nolta 18-70 AF DT kit.