It's not his fault! That cistern is a good few years old to have a ceramic syphon. At the other end of the rod is a disc with a diaphragm. I wouldn't hold out much hope, but it has been known that, with small fingers, to reach underneath to relocate, if lucky, (I doubt it) Push a nail or something through the hole in the rod to hold it till the link can be replaced. If unsuccessful, the whole syphon will have to be removed. If you have no plumbing experience, leave it to a plumber. You could run into all sorts of problems if you attempt this yourself with a cistern of that age.