processing your case.
If you have all the evidence which proves that you have inquired your cases and USCIS delayed processing it without justifiable cause. You may file a writ of mandamus with the Federal Court within your jurisidication.
Just got a case proved 9 days after serving the summon to USCIS district director. Before the lawsuit was filed, nobody gave a dime.
You can file it pro se (by yourself) or through your lawyer.
Good luck
Disclaimer: FYI only.