Horrible Service

I was happy to take my car on the 2nd April from kia Midrand thinking that everything was ok after the radiator cap fell off and tests were done to confirm that there were no damages. After two weeks of driving the car,I could feel that the car was not fine then I took it back to them on Saturday the 18th April. They told me they would work on it on Monday. Monday afternoon I got a call that the car had to stay for another day for more tests to be done. After that I was no longer getting any feedback from them about the status of the car. I was the one who kept calling day in day out. I only got one missed call from this dealer then I phoned them back and they told me they still did not see anything wrong with my car. I phone three times already this morning and they only tell me now that the head gasket is hurt. Had they warned me about this the first time the car was there, I would not have taken it and damaged my car, I phoned another kia dealer and they tell me that with overheating that is the first thing that should be checked. Now I have to pay out of my own pocket because of information that was not given to me initially that even with the new cap the car will overheat.