[pair of jacks]

the bungee cord hold downs on my rod racks run thru a small black plastic piece with a flat tongue to grab with your fingers to hook or unhook the cord. Some of those plastic pieces have broken off- does anyone know where to find these ? I have looked in every marine store out there with no luck. Some of the rod holders sold in West Marine come with the cords & pieces included but you can't just buy the plastic parts. Help !