DVD discs are quite resistant to surface scratches in my experience, which is why it sounds more like a manufacturing defect, as opposed to a scratch. I've also had a defective disc before, fresh out of shrinkwarp; it was definitely a flaw in the pressing of the disc.
You have three choices, as far as I know: You can bring it back to the store where you bought it, and they may allow you to exchange it (stores have varying policies on these matters). You can send it to the manufacturer, and they'll send you a new one (but it takes a while). Or, you just buy a new one and hope it was just a fluke and not an even bigger production problem (which happens, but is rare).