Late and defective renovation and building work

The responsible persons are husband and wife Carel and Sue-Marie Vos. They quoted for building working on my home and I was promised that it would take 8 weeks. In December 2015 it had taken about seven months and I had to put constant pressure on them for work to progress. It is now May 2016 and they have still not returned to fix or finish the outstanding work or defects as they had promised. I have since discovered additional defects in their work that I am either going to have to live with or will have to fix at extra cost. Carel Vos was supposed to project manage the work but was sometimes absent for weeks at a time. Employees of theirs often arrived without the necessary equipment or materials needed so work was done very haphazardly. Despite their big talk on the subject there was hardly any client service and they seemed to think merely answering my phone calls should be good enough (there were times when my calls went unanswered and were not returned). I do not take kindly to a person arriving three hours late for a meeting, entering my home without bothering to greet me and then ignoring me when I request to speak to him. Towards the end it became apparent that they did not have the knowledge or experience to do the work they quoted for and they admitted as much. On this basis they tried to convince us to agree to their not being responsible for specific work. Despite numerous requests they refused to discuss the financial implication of this suggestion. As a final insult they still have a piece of furniture I sold them that they never paid me for.