STOPPED WORKING??????????????

I have an MP# player wich all of the sudden has stopped working. That is if the memory chip is IN????? It will play music if I pop it out. Now Ive tried to repair it using the USB cable..still nothing. not only that Its like its erased about 25 songs that used to be on it!!!!!
HELP>>>>>>I use this to work out and now have the same 4 songs repeating THATS IT!!!!!!!!!!!!!!! I need to get this fixed AS FAST AS POSSIBLE!!!!!ANY IDEAS??????