Hello,
I am sorry to hear you were not satisfied with your purchase of our QuickHang Installation Kits. You can purchase each grid component in different lengths such as our main beams and wall molding that come in the kits at a 6' length but sold separately in a 12' length in black. These are sold in carton quantities. I have attached the link below for you to review each item number in our Prelude XL line.
https://www.armstrongceilings.com/residential/en-us/suspended-ceiling-systems/prelude-xl-grid-system.html#redirect_term=PRELUDE+XL+15%2F16%22+Grid+System