Worst service from Subaru Johannesburg ever.

My subaru Impreza Sti went for service to Subaru Johannesburg, we asked the service manager Ismail to check what was wrong as the car started spitting out white smoke as you drive. Got the car back, he assured me nothing was wrong. A month or so along the line, my car blew headgasket. I had to cover R23000 of the cost to have it repaired by them, but worst of all it took them 11 weeks to fix it as everytime ismail was on leave or something and then nothing was done on the car. So pathetic. And also to me it is not fair that we had to pay as we asked them to check and white smoke is an indication of headgasket failure. Will never use subaru dealers again.