Unprofessional and Incomplete work

We contracted Leon Haskins of Sandstone Innovations to build a stone wall on our property. He required a 50% deposit before commencing ,which we paid. The priority of the project was to build up a gap in the wall between myself and my Neighbour,which to date has not been completed. Leon was often not on site and on more than one occasion I had to stop his worker from doing the wrong things with regards to laying the foundation etc. Leon then stated that he had \messed up"and would we like our money back. To date we have received nothing. Leon has sent numerous emails and sms's in which he states that he should give our money back less the materials and labour which amounted to R8000. I managed to get a specialist stone mason in to inspect Leon's work and have the report which he emailed me stating that the rock was incorrect and the foundations were not laid properly. I hope that this letter will stop Leon from ripping other people off in the future."""