OSX my passport ultra 2tb not working

My passport ultra 2tb (one year old) is not working on any mac yosemite or el capitan
A white light is blinking but the disk is not found

Hello there,

Have you tried a different USB cable or port on the computers?

it doesn’t work on any MAC with Yosemite or El Capitan and any USB 2 cable
I sent a request that they change it

I sent an email and have no answer , when will they replace it ?