Poor service and communication

I've had the worst service experience from the service advisors, they (the ones I've dealt with) are never happy nor friendly. Then there was an issue of quotations, the first one was +- R17000 and when I went to pay it suddenly escalated to +-R22000 all this within three days and when I ask no one knows how it jumped meaning had I not noticed it I would have paid that R5000 extra. Then there was an issue of diagnosis, it seems their machines are unable to pinpoint the exact problem with the car because after they replaced the supposed faulty injector a turbo fault arose. Which makes me wonder if they're doing trial and error or if at all they know what they're doing. Almost forgot, now I'm struggling just to get my settlement amount. Take your car there at your own risk