blad 8gb not working

I buy a sandisk blad 8gb 2 months back,

After 2 days it doesnt work.

its work when thrown into air and catch it or shake well before use.

i used os windows 7 from 1st day of buying

what can i do?

plz anyone can help me, plz give suggestion.

Next time you get it to work, copy ALL files off of it, including any hidden system folders, then delete all file from it and return it to where you bought it.  There is something loose in it shorting it out and it’s just  matter of time before it fails completely.