IPOD 4 dock iPHONE 5 adapter NOT working?

So, I have my ipod docking station (which isn't an apple product, its eSONIC) and it works perfectly fine with any device that has the original charger plug-in shape, which inclues my ipod 4, and my ipod nano. I recently got an iphone 5 which has a different plug in shape to my ipod dock, so i bought an adapter online.
when i plug my iphone into the adapter and then into the ipod doc, my phone instantly charges, but when i go to play music, the music comes out of my iphone speaker rather than my dock.
My dock definitely works because when I plug my ipod into it, it instantly charges and plays music.
My adapter definitely works because when i plug my iphone into it, it begins to charge.
Does anyone know anything I can do to solve this? Does anyone have any tips/ advice?
anything is appreciated.

You can't buy a iphone 5 dock with a lighting connector compatible