Look up fabric stores in your local area and make calls. If they don't sell it, ask them if they know who does. Don't let the first person who answers the call answer, ask for the manager, or better yet, the owner. If they recommend a store, ask them if they know someone there, when you call, tell them who referred you. Pretty basic stuff, but if no one's ever told you how what I've just written, you might find it worthwhile.

Sean