ERP Project

Hi, I have project done by a programmer with a lot of issues which I need them to fix as fast as possible but the programmer is not responsive and I really don't like the way he does the job. The project is an ERP website for properties, which the agents can put up their list, which in terms will be shown on front end websites. on the backend there is ability to do reservation and accountant will be able to do the accounting part like receipt and all relevant approval. Also there is Enquiry managemen which the secratary is able to enter details and then sales manager able to assing an agent to it which can do the job and update the system that can be checked by sales manager and other authorzied persons.