G Technology Hard Drive

I purchased the above hard drive, and sadly it doesn't work properly.    

When I connect it to the USB drive, sometimes it takes over 30 minutes to recognize the drive.  If I accidentally forget to EJECT, I have to wait over 24 hours.  

I contacted the merchant, and they were not helpful.  However, I can return the device.  Unfortunately, I forget to check the reviews from the Amazon customers.  There, I found out that device adversely affects MAC computers from OLD to NEW.

Any advice?

Thanks