This is excellent advice. I can also confirm this gets faster results. I only know very basic mandarin but google translate does the job as long as you keep it short and to the point with no slang.
I think what probably happens is that all issues go to a guy who gets too many emails, he then fires off a pre baked reply, if that fails they send something asking you to take images and videos, then after that they seem to try resolving matters, but with a reply in Chinese it misses a few steps, at least for me anyway.
Just out of interest i once got a non working flashlight and they eventually asked me to take a video of it as proof and add to youtube. I did that and they sent me a new unit, here is the strange thing though, looking at viewing stats on that private video still to this day shows NO views. So i am assuming from that they just get you to jump hoops but dont even check! almost like its company policy to try and put you off at least 2 times before they start to do their job. That’s just my thoughts on it anyway.

Fingers crossed your issues are sorted out soon.