ipod shut off..and wont turn back on

soo my ipod (new 4g, 8GB) just shut off randomly. It did this to me two days ago...i talked to a friend and he said to plug it in and wiggle the charger where it plugs into the ipod...so i did and it worked!! but, it worked for about 4 hours then did the same thing. so i tried fixing it the same way but it didnt work. i left it plugged in all night and all day but it still will not work! someone please help me!!! i have only had it for two months. and i would like to know what is wrong with it....that ipod wasnt cheap