patnams,
as far as I know, in general lawyers are there to make money just like you and me... like you said, they are humans, and hence they are prone to make mistakes. If you have a strong or even weak reason to believe your lawyer lied, you should find someone else or some other way ...
as for the answers to your questions, I filed AC21 myself, my status did not change nor did i get a receipt notice ( receipt notice for which application ? ) and I dont blame USCIS for that... its a new law and they dont have a procedure yet.