Poor service and detection. Conauto, Boksburg

My Figo went for its annual service at conauto Boksburg in Aug and got a clean bill of health, only to find out 2wks later, the clutch, starter and fan motor has failed to the amount of 18k. How is it that this was not picked up? The service manager called me and said that these things happen. I find this inexcusable as they plead ignorance. I'm so irate as they have been servicing my car since new