I've had a few with gunmetal hardware chip/scratch. The yellow/ostrich ($1200), and the green. So disappointing, because both colors I definitely want to keep. I don't think it's something they will repair - rather offer you full credit back, or let you keep the bag, and offer 30 or 40% off a bag of your choice (Rogues included). Regardless of where you bought it, I think Coach should stand behind their merchandise. Unless you have an established relationship with a store, I would call Coach customer service (during the day, so you actually get the corporate offices), and find out what they're willing to do.
I think Coach needs to stop using the gunmetal hardware until it's perfected. They've had many problems with it over the years. Until then, I'm sticking to the brass hardware on the 1941 line.