Negligence and bad customer treatment

I took my car to Menlyn Landrover for replacement of front shocks only but my car was quoted for most of the things not damaged. I accepted and pay that. Now, after collecting my car it is having a loud noise when accelerating and I took it back I was was told its a PTU leaking and I started to question why not picked up during three diagnostic tests done, and the answer was the Technician saw it, i then asked why you never let me know about it. I was given a car and never been told about it and when I book in the car there was no problem. Around May I also send the car for rear shocks, during collections all battery were dead (main and auxi****y) and the car was having many problems or warning ⚠ signs than when it was booked in.