La Perfumerie V&A Waterfront

I visited the La Parfumerie store at the V&A Waterfront on Sunday evening and was excited to see that their fragrances were more affordable than Edgars. I purchased a 100ml Guerlain fragrance for R2000. I verified with the very friendly shop attendant if it would be possible to return the fragrance if I changed my mind. The next day, I found the same fragrance at a better price elsewhere. When I went back, the shop attendant told me she could not refund me as she did not have cash and asked me to return the following day. When I went back the next day, she said her boss had forgotten to leave the cash with her. I decided to phone him so that I could avoid driving all the way to the mall repeatedly. Before I could explain myself, he shouted at me, told me he would not refund me and told me not to complain or create trouble for his store, that he knows everyone in Cape Town (was this even relevant/necessary) and that I should never visit his shop ever again. He then phoned the shop attendant who I honestly feel sorry for and shouted at her in French. She apologised profusely and told me she would do everything she can to sort it out. 30 minutes later he phoned me and again shouted at me telling me never to return to his shop again. I could not let this go as I am offended by the way I was treated as a customer in that store. I also don't understand the aggression and paranoia over a simple refund request in such a prestigious and high-end shopping mall. Does anyone know what I can do to have this resolved?