Brake lights won't come on?

I have replaced the fuses and I have replaced the bulbs I have replace the brake switch. I have a problem still no brake lights. All lights working tail lights and blinkers work just no brake lights? I even check the fuses floor box and under neath. My hood fuse box. I now can't get the brake switch on the brake pedal with a clip. I can't get the brake lights on either. Help me please...