Thunberbolt Duo and My Book 4gb not mounting in Mac 10.10.3

What good is testing the drive on another computer?!? I NEED this to work on MY computer. So it works on another computer, and I can copy the data onto the Thunderbolt Duo that won’t work for me?!? It was marketed and sold to me by WD stating it was formatted and ready to work on my MAC. Is there going to be a patch to make this work on Yosimite. Unaccaptable. I hope this issue is resolved, soon. This should have been resolved weeks ago. I am a longtime user and had confidence in WD, I will not spend another dollar on a WD product, totally unacceptable. My livelihood is being impacted. I am losing money and clientele every day!. I’ve got 5 years of work lying on my desk useless and unaccesible and a brand new 8TB paperweight. [Deleted] . Fix it.