from a congressional caseworker
because i happen to be employed as a immigration caseworker in a congressional office, i have an idea how to answer this question! i'd suggest, as the person above wisely did, that you check the website of the congressman/woman or senator from whom you are trying to obtain assistance. these sites can be found at
www.senate.gov or
www.house.gov. congressional offices require written consent to inquire on your behalf, and in my experience, it's also helpful to have a time line of action taken on your case and what specific goals you are seeking. another safe bet is to just call the main office in the home state/district and ask what the procedures are for opening a new immigration case. it is not necessary to speak directly to the immigration caseworker or the representative him or herself--they can't tell you very much until they have the paperwork they need.
please know that every congressional office is working simultaneously on many immigration cases, so it is very likely that they have heard a story very similar to yours in the past. this is not to discount the frustration that you are experiencing--just do your best not to keep a caseworker on the phone for 45 minutes to complain about the name check process or some other problem that we encounter every day. believe me, in most cases, we *know* it is a problem, and we would much rather spend that 45 minutes working on cases that we can actually make progress on.
as an aside, i also want to bring up a point about contacting multiple congressional offices. please please don't do it! uscis offices only allow one congressional office to work on a particular case at a time, and you will only be causing frustration and wasted effort by contacting more than one office at a time. if you find that one office is not helpful, please do us all the favor of requesting that the office close the inquiry and notify the CIS. then, when you contact another of your representatives, please let them know that you previously closed out an inquiry with another office in favor of theirs. it seems like a silly thing, but i spend a good portion of my day working on cases only to get the answer that "so and so needs to see senator whomever, who is already working on their case."
if you all have any other questions about contacting congressional offices, let me know. i can do my best to answer general questions about what offices are and are not able to do and give you some idea about the process from our side of things.