Unfortunately it would cost more to send you some from the UK than you can buy it for there, plus the fact that I only brought a couple of thongs with me from my old house to the new one so have to wait a couple of years for it to be viable again.
But can I give you a tip? If you can't get a swap, don't buy it from a nursery. Just wait for the right season and buy a single thong (root) at your supermarket. But do make sure it's fresh. If it's pre-packed just buy the smallest amount possible (a lot cheaper). Once it takes it spreads like wild-fire.