Try blind shops? As in shops that sell curtains, roman blinds etc because you need those chains for vertical and horizontal blinds too right? Maybe look up the Yellow Pages and give a couple a call to ask if they sell the chains separately.
Another ditzy girly suggestion - use a long tassle. I saw some for sale at the B2 atrium of Ngee Ann City yesterday. About 1 metre, available in light and dark brown, usual priec $49 now going for $10. What a bargain!
