Just a follow up to my original post a few weeks back. After my trip was completed I ended up with 4 out of 6 segments posting as "not eligible for mileage credit" despite this being a paid F ticket. I sent DL an email explaining the situation and requesting credit. I received the auto-acknowledgment of receipt of my email with a note it could take up to 30 days to receive a response. Well today marked two weeks since I sent in my email, and while 30 days definitely had not elapsed, I had never waited this long for a response before. I decided to DM Tweet DL and see if that brought me any luck. To my surprise I received a DM back within the hour apologizing for the delay, that emails were taking almost 30 days to be responded to, but the agent offered to help right away with the Skymiles Support Dept. The agent then advised that the Skymiles desk had re-submitted the trip for processing and the correct mileage should post within 24-48 hours. I thanked the agent for the help and went about my day (actually heading to the airport for an AS flight). By the time I got to my departure gate I checked my DL app and the processing had completed with all 6 segments posted with mileage. I think I might've been slightly shorted MQDs, but overall I'm happy. Moral of the story: check your mileage earnings carefully. And I haven't had good luck with DL twitter in the past, but overall very happy today!