Trouble starting car

I have a 2002 Ford Focus station wagon. For the past 5 months I have had trouble with getting it to start. It will go several days or a couple of weeks with no problem then it will act up and not start 2 or three times a week. Usually it does this in the morning but it has happened in the evening. I have taken it to the Dealership, they have replaced the fuel pump, fuel filter. I still had problems so they took it back, kept it for 10 days and every day it started for them. I have had the car back for two weeks now and it has not started for me 6 times. I am very frustrated. Any ideas??

Find yourself a good independent mechanic

Walk outside.  Look at your car.  Is it parked on a flat area, or is it parked up hill or down hill?  Is it in a garage or outside?   Now think back at where it was at the dealer?

When you turn the key, does the starter work? Does the starter turn the engine over at normal starting speed? Or does nothing happen?

You have to define “does not start.” Tell us EXACTLY what happens when you try to start your car.