@savolife G-28 on its own does not solve the problem with case processing. This form just notifies USCIS that a lawyer is now representing you. This may be helpful if you get RFE / interview etc. But does not speed up anything. Writ of Mandamus is one solution, and unless you do it yourself, going to cost several thousand dollars. If you end up hiring a lawyer, at least search the State Bar of <your state> directory to make sure they're real lawyer.