Are you using a bleeding tool or just doing it manually?
I assume you have two people doing the bleeding.
I saw a tool you can get at CI that makes the job easier and one person can do it.

Did you bleed them back to front in the order Vikky stated?

Have you successfully bled your brakes before?
Do you have someone close have a look at what you are doing. A second eye sometimes helps.

Are you refilling the master cylinder every time?

I'm assuming your bleeding correctly but I will state the procedure I do to see if we are both on the same page.

1. Driver pumps up the brakes, tells dude at RR to to bleed
2. Driver tells dude to close b4 the petal hits the floor
3. Move to LR and do same thing
4. Move to RF and do same thing
5. Move to LF and do same thing

You need to add fluid if you get low in the m/c while bleeding. Start over if m/c goes dry.
Always collapse the rubber in the lid b4 putting lid back on.

Start the car and test.