Check that the caliper slides are free to move, change the brake fluid, and deglaze the rotors.

Yeh plenty of fluid and ive already roughed up the pads and rotors with course sandpaper but still nothing, what are the caliper slides? are they the piston things that push the pads in as they wear out? (sorry dont know to much on brakes)

The slides are the pins that the caliper housing slides on.
Another trick is to remove the little stainless steel shims that the pads slide on, and apply a little Grey Maxx silicone to the underside of them where they contact the outer bracket that locates the pads. This acts as a vibe barrier from the pads.
Have you checked that the rotors aren't warped ???
Are the wheel hub assemblies noisy when you spin them by hand when the rotors are off them ???
Is the inner mating face of the rotors clean and rust free where they sit on the wheel hubs ???

These are front calipers off a Camry that I have reconditioned.....can you see the little black boots where the caliper meets the outer bracket....thats where the slide pins live.
E series, A series and B series calipers have the same idea basically.
I use silicone grease for them, it doesn't hurt the rubbers, and it's water proof if/when the boots perish/split and lets in the elements.

 

 

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Ok thanks heaps for all that info really helpful, next time I have time il take the wheels off and have a look, roters could well be warped probably couldn't hurt to get them machined. Also even try a different brand of pads maybe if all else fails but one step at a time. Thanks again