When I talked with the client for the first time, we didn't set well stablished limits for the project. The project is a mobile app. The agreement was that I was going to copy a Web App he was finishing. At that point, the project didn't seem too big and we settled a price and a deadline.
During the development, he continued adding features and making changes to the Web App. At the beginning it was little, but then the project became larger and larger. The deadline came, but they agreed to add one month in order for me to finish. Then he continued adding features and every time I told him it wasn't the agreement, he found a different way to evade it.
Now, I'm at a point where the extra month ended and he and his partners are furious because it isn't finished (Which is obvious because he just ended the app one week ago and I'm still adding that features). I haven't received last month payment and we don't have any contract. My client is calling me every 2 hours and writing every 15 minutes to see how is the project going and forces me to stay awake at night, threatening me if I don't.
Each time I'm presenting the App, he still finds a difference from the Web App. This is no longer business. ¿What can I do in order to end with this situation?
PS: My client resides in another city and wants to come to my place.
Thanks for all your answers.
After a week I couldn't avoid my client to come to my city, but I saw him just to negotiate. We agreed to finish a couple of things in order to get the full payment. After that, they went back to their city and I stopped working.
Back in their city, the client tried to continue with the development again (without paying) so I didn't continue. I tried to call him for a week to get paid but he didn't answer. I wrote him telling I wouldn't deliver any of the latest code and I blocked him.
Next day, his boss called me. He told me he removed the person who hired me, from the project. He was going to continue with this. After a long negotiation, we agreed he would pay me the half of the last payment, for the development at the point it was.
Thanks for all your answers. Sorry I didn't updated this for long time, but I read all your suggestions and all of them where useful. I'm working on every point you told me to avoid falling into this again.