Acoustic Solutions MP3 wont do anything?

I have an Acoustic Solutions MP3 plater, model 513/4696 but cant format it, delete files or basically do anything with it. I downloaded some music as I have always done, first onto my son' and then onto mine. His stopped working first and a few hours later so did mine. I can sometimes get information showing about the few recordings left on it but cant play them or delete them. Sometimes it wont do anything and turns itself off. I have tried to format it but my computer wont recognise it just states that there is a problem. I have had to get a cheap replacement but its not the same and would really like to get my original one back working again. Can anyone help.