Recently i have bought a SanDisk 16GB Micro USB 2.0 OTG Pen Drive, now i have a problem with that pendrive, when i copy a file and then unmount pendrive. And again try to open saved data in that pen drive ,but unfortunately the data gets corrupted. How to recover the problem. (Note :- i have format the pendrive using android phone before that i try to format the pendrive in windows8 but unfortunately the formatting have not completed.)