Worse off than before

I was contacted by On Air in Sept 2015 and was sold a Explora decoder.I have a Sony Bravia TV 40\ and no sound comes through the TV speakers.I have to play the decoder through my Hi Fi.On Air maintain that my Sony Bravia Model Model No KLV 40 V 550A year 2010 is not HDMI sound compatible .the sound through the TV with my previous DSTV decoder was absolutely fine and now am subjected to this<br> As far as Im concerned this is false selling .I was not asked once whether TV would be compatible or not.<br> Im not happy at all.Please advise<br> -- "