Repairs not done.

After waiting for many weeks for the parts to arrive to fix the brakes and window switches on my fiesta, I received a call from ECM saying that they want to install them the next day. So I arranged my day for them to fix my car but they chose to replace the broken window switches and leave the brakes which I find very strange. I thought they would start with the safety related problem then replace switches. The excuse was that they haven't fixed the braking system before so they didn't know how big the job was. Shouldn't a dealer know these things? Now I have to take time off work for another day and drive with faulty brakes until I can get the car back there. So what happens now if I crash due to brake failure?