Very poor business ethics and service

I contacted Ron about my EDU he was very quick to say they have stock and it would be R6000 , I went to the branch and I took my old EDU with with testing to make sure that , this was the issue with my car , I was called 2 hours later and told the EDU was faulty beyond economic repair , so I would need the replacement unit. So I paid the money and took the unit to the mechanic, with in 20 min of me leaving the mechanic called me and said the unit is faulty could I please bring my old unit back , I took it to him within 30 min he called and said my car is running it was a small problem with the EDU that has now been repaired , I contacted ECU express and informed them that the unit was faulty and I was brining it back , I was told that they would have to test the unit and this would take 1 day (mine was tested in 2 hours ) and once testing was done they would give me feed back the next day , 3 days past so I called them and was told the technician will call me with in the hour to explain it's now been a further week and no call from the technician or Ron who now doesn't answer messages or calls and still no refund. I would not recommend this company to anyone and further more I will be taking the case to the motor Aumbustman as well