SanDisk 64GB Ultra Backup USB Flash Drive

I bought this on Amazon 3 Nov 2012 and it has been working fine.  Today though I noticed the indicator light wasn’t on and when I checked further the drive it’s plugged into shows nothing there.   I removed the SanDisk and tried it in other usb drives on this and another laptop but no indicator light and no drive/files shown.  I also tried another flash drive (not Sandisk) and this worked fine on both laptops.

What has happened and what can I do?  I’ve been googling and I have a horrible feeling all my data is lost. :confounded:  If that’s the case how do I get a refund or replacement? 

Thanks in advance.

SanDisk Customer Service/Tech Support

Thank you.