Bad service, would not recommend it to anyone

I took my little brothers car in for repairs at Qwa Qwa fitment centre (Point-S) on the 10th May 2019 due to the fact that it was idling rough. I drove the car to their workshop on the 10th May 2019 to get it checked than upon checking i was told that the head cylinder had to be removed, so i was given a quote, i than left the car and later paid the quote in full, a week thereafter i was called to collect the car and upon inspection i noticed that the car had no idling and also no power and than i asked for a pressure test, tested it myself and found out that they bent the valves upon installing the head cylinder, i than instructed them to fix the problem by inserting new valves, after they took off the head cylinder i noticed that they had cracked and damaged the head cylinder, they than assured me that they will by another one, of which they did buy a second hand one but i was fine with it as long as it worked, was installed and the car did not start than they got in another mechanic who told them that they ****ed the engine because there was no compression from the engine block. Than again i was promised that the matter will be resolved and a replacement engine will be fitted in by 22 June 2019. I than discovered that there were 6 more vehicles that were stripped and had been left for more than 6 months, due to the fact that the mechanics there do not know what they're doing. I urge legal advice regarding that vehicle and in anyway that RMI can investigate in that matter plus the other 6 vehicles which i have pictures of. No one there is qualified to do what they're ****