Fountains BMW the technicians dont know their jobs take your BM somewhere

The worst experience @Pretoria BMW FOUNTAINS.My husband tooK the car it was overheating and they charged him more than 8000 Rand and they called him on thursday the 7th that the car is ready,we collected and within driving the car for less than 20km it started to overheat when we reached Pretoria west ,we towed the car on friday the 8th and the guy called Rian told us he tested it the previous day for about 10km and it was ok,when we chacked with the TRACKER the car didnt reach the kilometers that he said,which is very unprofessional of him to lie to us.He told us he replaced certain parts and when we requested our old parts he said he doesnt know where the other parts are and he brought one part that was not what was on our car it belongs to someone else and he wanted proof to say it is not our part ,his arrogance is beyond this world.We went there with the hope of the car being fixed but it came back the same and were told they will do a diagnosis again and they will charge us ,and the first time they assumed it might be a problem it was not properly diagnosed .We want our refund and they take back their parts there is nothing they did to that car. They are very useless they are not better than the guys on the streets.Pathetic service from BMW FOUNTAINS ,.When were there another car came and it was the same issue.