How do I handle an angry client in an underestimated project?

Hi /r/web_design !

I'm working for a small web start-up and when we started the company few months ago, we accepted a project which consisted of developing an app. It was an interesting project with deadlines that we thought we could handle. The first steps of the project went well and we reached each deadline on time. But now, we are at the end of the project and we realise how much we underestimated the scope of the project. For your information, our contract doesn't stipulate any fixed deadline, just time estimation per development steps and a fixed project price.

We are already 2 weeks over the final estimated deadline and to be honest, there is still a lot left to do. We were expecting to have a beta ready several times in these 2 weeks but each time, we underestimated the amount of work left. It brings us to today: we have worked almost triple the amount of hours compared to the initial estimation. We would like some advice on how to handle this. We understand that the client is angry because we are over the deadline, but in the same time we are the one who has spent 3 times the amount of hours we estimated plus working both weekends and evenings. They will get the app really late, but also at ~30% of the actual cost.

We are being completely transparent with our client, but now they are really impatient (borderline angry/menacing).

It really sucks to be developing at a loss and only get negativity from the client. Any advice on how we should talk to them?

Epic visual tool

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