Bosch car service Cencar

We took our car to Bosch Cencar in centurion. They qouted us on our dieselpump for our car. We agreed that the dieselpump wil only be tested and calibrated. After the work was done we received another qoute charging as double. Work was done that we did not want and they just said we have to pay it the work is already done. I am disgusted and dissapointed. Really.