UPDATE: After multiple back and forth with the missing stay team, I finally got credit for my stay. I never did get a response to the initial complaint. I consider this whole matter closed.
Bottom line: the hotels do whatever they want, and MR customer service, missing stay team, and lurker cannot/will not do anything about it.
This latest episode, along with all the effort to get receipts, stay credit, and stated MR benefits has really made me tired. I've reached 75 for the year and have booked my remaining paid stays for the year with HH and IHG and will resume with Marriott in January.