After 90 days I successfully appealed my denial
On March 5th I submitted an application to register a lower receiver for a featureless build. Needless to say it was denied for barrel length issues(not sure what happened there). Anyway, I didn't know why it was denied until this week. I have been calling almost every week and even went in for in-person visit. Nothing helped. Noone was giving me a straight answer on why it was denied, and no denial letter was sent. I made 12 phone calls, 2 emails and a couple of in person visits. Everytime I called I was told they'll send it out but they didn't.
Anyway, I went in this week and asked for the reason and they told me it was the barrel length. And also the nice lady at the counter didn't even know what a lower receiver is. She kept asking me "what does this attach to?". I kept explaining the lower receiver IS the firearm but she couldn't get it. After a long discussion and going over the city code/law on the AWB she finally got it. I was annoyed but I was glad she took the time to understand and learn about it, instead of giving me a packaged answer and sending me away. I'll take that over being sent away with nothing tangible.
They are now requiring pictures of the firearm now, so I went to g&d assembled the rifle took pictures and used gemini to create a nice info graphic cross referencing the law with the parts on my rifle, and voila I got the approval. I'm glad this long and confusing ordeal is over. I hope I never go through that again.
P.S - Thanks r/lawblawg for the help.