Unprofessional & unethical business conduct @ Hoc Tuning / H.O.C Performance Tuning

S****ed individuals with good knowledge of Opel vehicles. However, terribly unprofessional service and business acumen. There is only one highly s****ed technician who is often not at the workshop but busy pursuing other business ventures. Customers are expected to wait until this gentlemen is available as there is no other technician capable of assisting in this capacity. Terrible customer service. I was verbally attacked by the technician Selwyn telephonically who refused to assist me any further for reasons not valid. Despite there still being a warranty on the work done to my vehicle, he refused to assist me any further or to work on my vehicle any longer. He made assumptions regarding my intentions when I attempted to consult with him regarding my vehicle and additional research I had done on trying to understand and diagnose the problem areas on my vehicle. He accused me of undermining his professional opinion and reacted in an aggressive manner, which was totally unfair and untrue. He has no professional tact in dealing with customers or any respect for women. I was humiliated and belittled by this man due to his assumptions which was not true whatsoever. Nor was it called for. My first and worst experience in engaging with persons from this industry.