I've made progress, but have bad news. I found the Concord sofa at Kmart.com, but it is 'temporarily unavailble'. http://www.kmart.com/shc/s/p_10151_10104_07180285000P
Because your Sears store doesn't seem to have it either, we must assume they either stopped production, there is a problem getting it from distributors, or they may have discontinued the line.
My only suggestion is to keep checking back with Sears and Kmart to find if they have gotten it in, or if they have the means to order it from their distributors for you. Also, ask if they can contact any other stores, perhaps out of your local area, to see if they have any in stock, and then ask for it to be shipped to your local store, or directly to you. If you bought the set at Sears, their Customer Service department should be able to check for you, to know whether they will ever stock this line, again, in the future. It does seem strange that you bought yours in September, and in January, there is no trace of it? Perhaps it's a 'seasonal' item, because it's a patio set, and they might get more stock after the winter is over.
Here is contact information for Kmart: 1-866-KMART-4U
(1-866-562-7848), from 6 a.m. to 12 a.m. (CT) Monday - Sunday.
E-Mail us with questions or comments.
Sears Customer Service: 1-800-349-4358