*update*
So after reading all your replies i have replaced the master cylinder...no difference.. re-bled the master cylinder twice and re-bled all 4 lines several times...no difference. Then i was concerned i had air getting into the system so i pressurized and went around to every joint/connection with a squirty bottle with fairy liquid....no leaks. My next thought was that the master cylinder was not man enough to move 4 pistons, so i blanked off the 2 rear lines at the master cylinder, re_bled front 2 lines....no difference!
ive got to the point now where i could cry! i cannot for the life of me think what else it could be?? the only part of the system i havent touched is the servo? what are the signs of a failed servo? i always thought the pedal would go hard not the opposite? please help!