I would start by asking to have this thread deleted honestly.
Understand you are putting your job in jeopardy. You may be the 'whistleblower' and also lose your job for doing so.
With that in mind, I would suggest that this is fraud and state to the highest level person who is aware of what is going on what it is. You may not have all the information and this might be a viable solution.
Seek to understand the full process before calling it out. If this it outside of your work area, you may want to sit on it and let it play out for them. I can't honestly believe a company would replace 40 HDDs without starting to ask questions, or want one of their techs on site, or someone there to figure out why there is a such a high failure rate.