A lawsuit in the Federal court may speed up

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.