Citizenship

My application was denied by uscis today . I had applied under 3 yrs rule since I am a spouse of US citizen . The officer claims that since I had been a permanent resident since 2013 I can’t apply under 3 yrs rule which I couldn’t find anywhere in the law which stops me to do so . My officer didn’t give a decision for 199days unless when I conveyed through congressman that I will go to the court if they did not send me a decision by may 25, 2020. They gave a decision on may 21st which I received today which i guess is not based on law since the officer didn’t mention it either as where the law says that I can’t apply under 3yrs rule. Anyone who knows a great lawyer whom I can hire to make an appeal against this decision . Any other suggestions ?.