Poor service and a lack of professionalism from BMW Midrand.

Had my car taken there after a diesel contamination. Vehicle was quoted and the fuelcompany responsible paid fix the repairs. Was told the vehicle was repaired and I took delivery. Two days later, the vehicle lost power and cut out on the N1 South. Returned the vehicle at own cost to the same dealer. They diagnosed a faulty fuellevel sensor to be the problem. The sensor was part of the equipment replaced and not ****aged by the contamination. Now...after 2 weeks BMW SA found that it was not due to faulty workmanship, but ****age due to the contamination! Where is the ownership and accoutability?