Sometimes heavy duty clutches can confuse the fook out of the clutch ratchet mechanism! Get under the car and have someone push the clutch to the ground if the mechanism isn't moving sufficienly to disengage the clutch then you will have to try adjusting it manually by placing a bar behind the clutch fork when it is half way across to stop it from moving and then release the pedal and it should click several times on the ratchet! This should work if there is nothing broken inside the box/clutch!
If you don't understand what i mean bell me tommorow as its easier to explain on the blower