To try and make it simple for you try this ,
take of your pedal box cover to let you see what is going on ,
if you slowly pull the cable back and forth you will see the pedal move up and down in the car ,
you want the clutch pedal to be just a tad lower than the brake pedal ,so pull the cable out to this position and adjust the two nuts up to the bulk head and this should be fine .good luck
If not phone the bugger up and tell him he has not done his job right . 😬