My flights were booked thru MH website.

An update to my case and some information that might be useful for others. The missing flight is finally accounted for today after I called them again last night. Initially the agent said she couldn't do anything as the records in the system don't show any progress, no trace of the BP (so confirmed they don't keep a copy of the BP in system), and the system does not even show the agent who's supposed to follow-up (later on this). I said I have a copy of all those and asked her to follow up for me. She said she'll try and asked me to email the PDFs to her. Sure enough, it's done today so they can fast track it if they have the right information and an agent who's willing to help. Could be just a coincidence of timing, but I'd rather believe she cared for me

Information that might be useful for others. She asked me early on if I mailed in the request addressed to a specific agent. I said no I just followed the instructions and posted it to the club.
- She told me next time, call in first and talk to an agent, ask for the agent's name and say you'll send in the request to her. Mail in the request with attention to that person.
- That agent will be the one who is supposed to follow up the case for you. For any inquiry, you can ask for that person or ask any agent to ask that person since she's the one (only??) who knows the progress
- She said if the request was posted to the general club mailbox, a random agent would open it and is supposed to follow the case, but you don't know who to ask for. And, the agents themselves also don't know who to ask either if you call up!!

It's silly that customers need to worry about this, but anyway it might help next time if you need to do it again.