I have two sets of full length curtains each end of my lounge. The track is one of those with a cord at one end which you pull to draw the curtains across. It seems that both are broken as one doesn’t work at all and the other only pulls one curtain. Are these repairable does anyone know or do I need to buy new tracks? I can’t see where the cord goes behind the track, but then I haven’t taken them down yet. Thanks.