Good performance poor quality

I added this memory my 3 months ago.
He initially worked well properly and has fulfilled all what I have asked of him. Meanwhile, my picture has worsened it because my "blown" during operation one of the two bars is and is no longer functional.

I would say nothing if something happens after 1-2 years, but after 3 months, that's just not acceptable.

3 stars anyway because the support is good, and I assume that such production errors are very rare.