Part of me wants to grab these clients and shake them while yelling "You are a software company, why are you farming out your core competency!?!?" These problems arise because the client thinks that the software portion of their business is just a tiny part of the picture. If the only thing your clients use to do business with you is your mobile app, then you are a software company. Full stop.

Why the hell did they hire a designer? They need a product manager. And why are they building the entire solution in one shot? Build it in small pieces and iterate.