You can reduce the sound by putting some foam material under the PCB, so that the foam would build tension between PCB and the bottom case. (At least, this method worked for me on my G80-3700 numpad. I didn't think PCB mounted boards would ping, but it did. The fix didn't completely get rid of the sound but it reduced it significantly. If I put more foam inside, I might be able to eliminate it, but I am content with my current fix, so I wouldn't bother.)
However, this fix would void warranty in your case because disassembling it would damage the warranty sticker. The pinging/ringing sound is pretty much unavoidable (yet very annoying to some people) in most mechanical keyboards with springs, so if you are bothered by it and not willing to fix it, I think it would be best to return it.