I want to keep the story short and clear:
Let us know within five days, if you think you are being wrongly penalized due to the false positive that MOSS has thrown.
On 2020/6/23, I replied with a new e-mail to ask for the progress.
Until 2020/6/30 13:50 (UTC+8), I haven't received any reply to the e-mails mentioned above, and my solutions are still disqualified.
Without any reply for days, I began to think that I might have sent the e-mail to a wrong place again. In the first e-mail, I was only told to "let them know" without any instructions on how to reach them.
However, I heard that some people got a quick reply after writing a blog post, so I guess this is the proper way to reach CodeChef admins.
I hope that "writing a blog post" can be added in Contact Us so that no one will be wasting his/her time on writing e-mails to CodeChef.