Worse than ever service in my life time

Very very bad service no communication and different feedback from different people in business. They are not honest. I took my car for engine rebuild on the first week of December last year and pay them R62312. 47 on February but still my car nothing happened it's been six months now and I'm the one who always go there or contact them to find out what's going on and they told me that they are waiting for pistons they did order a wrong one before. They can't give you even a right time it's like they don't no what's going on with their suppliers. I want them to give me my car and money because they fail to give me service. And my car it's getting damaged because of dust and rain. I was willing to put some documentation but there is no option.