Mobile development issues

I have no coding experience so Iam not conversant with this. However, i have a mobile app that is already launched in the market. However, it seems to have issues with some key features and my developer is not keen on correcting these issues. What are options in this situation? Is it possible to have a different developer look at the develope.t or source code and identify /fix the issues without running the risk of taking away my source code or breaking things even further ?