Car went in driving and now I can't drive it I'm ex extremely disappointed in Dunlop fish hoek

Car went in driving and now I can't drive it I'm ex extremely disappointed in Dunlop fish hoek. My car went in idelining perfect had power . Had work done on my car. Got it back no power it's idelining wrong my just cuts out when I'm driving. Something needs to be done I spent R24000 on my car. Had to take my car back 3 times and now there's no response on their side.