Sansui DB-100 problem.

I have a problem with my Sansui DB-100 DAB/MP3 player which was bought last November ... When I charge it up overnight, it will not start when I try to switch it on in the morning ... During charging the red light is on and when the charge is complete the red light goes off as it should ... When I try to switch it on, the green light flashes as it should, but then it switches itself off ... If I connect the charger for a couple of seconds, it will switch on OK ... It is as though it needs a quick jolt to get it to work ... The battery is OK and holds its charge OK as I left it playing on its internal speaker for 12 hours and there was still plenty of power left (according to the display) ... Sansui say that I should return it to the seller, but they are no longer in business ... When it works, it is great and the sound quality is all that I need when away on holiday or travelling ... I have an 8Gb micro-SD card in the DB-100 with all my favourite music on and the sound quality is great ... The unit is sealed and the battery is a Li-Ion, so I can't have a look into the workings ... I hope that someone out there can help to resolve this problem ... I don't really want to throw it away, but if I do, can anyone suggest another DAB/MP3 player to replace it ... I have told Sansui about the seller being out of business and have asked if I can send it to them to be tested ... I am still waiting for a reply.