WD30EFRX Warranty back, and failed again!

I can’t believe that this happened to me.
I bought WD30EFRX for my Synology DS3615XS NAS.
It failed after 3 months with a lot of bad sectors.
and then i send for warranty early of march 2016, they replace a new HDD,
and it failed with bad sectors again.
I reformat it, fixed the bad sectors, and it failed again.
I done second reformat, fixed another series of bad sectors, and it failed again.
oh my god.

I’m wondering if the issue relates to the enclosure itself after so many disk drive failures. If this enclosure allows you to change a drive’s bay and working drive now fails then the issue could relate to the controller in question affecting your disk drives.

Is OK, i already ask for second RMA.
Going to send again to vietnam for second time.

I am running kingson 120gb SSD and western digital 1TB green on same machine too. so far everything works fine. the western digital 1TB green was 6 years old today. Both of them 0 bad sectors so far.

3TB red has 8.8% failure rate