Where do you buy double wall oven frames? Our family basically bought double wall ovens and we asked at the...

Our family basically bought double wall ovens and we asked at the place we bought it at(Sears) and they said any hardware store. When we asked at Home Depot, they said DIY(do it yourself) or ask where you bought it. I really don't want a DIY, but does anyone know where on earth to buy the wood frame that goes around the wall ovens that they hold on display like on the stores?