Here is my experience regarding talking with USCIS support. Today I've called to USCIS one more time and asked a rep to talk with tier 2 officer since I have not received a biometric appointment for more then 90 days from the application filling. The lady said that she can't transfer the call to tier 2 officer and I shouldn't worry about the delay since all offices have a huge backlog for biometrics and I just need to wait (it seems they always say that default text). I replied I'm aware about the backlog, but my case has a very strictly timerange for processing as all other DV cases. The lady said that she sees my case as a family-based adjustment application in the system and that the normal processing time is from 13 to 27 months for those type of cases
I don't know if an USCIS representative can really see the type of the case in the system, but it was my chanse so I pointed out an error in the case type and the lady agreed to submit request and said that tier 2 officer will call me during 7 days.
I'm not sure that this will work for everyone, but ask UCSIC rep to check the type of your case in the system if you have not received an update for a long time.
Sorry for the long message, just wanted to share more details. Hope for the better for everyone!