It's a bit strange to think of representation only if your candidate wins. By that definition representatives (PMs, members of the house, house reps, whatever they're called) would stop being representative the moment someone loses against them. And there are a lot of contested electoral districts. (Sadly there are quite a few uncontested ones too.)
The quality of representation is a different matter. But yes, (representative) democracy is broken. Just as any collective policy making strategy that requires an expert majority.