Thumbs down on how to speak to customers

I recently took out two contracts with Telkom in Walmer Park shopping centre, both of which included Samsung S9's. I was assured that I could return the phones within 7 days should there be any faults or concerns. 3 days later I returned to advise them that I was having battery draining problems and wanted to know more about the OBF policy I was told about. I went to a Samsung repair store in Newton Park as I was wrongly advised to, never the less they did not touch the phones and told me to take them back to Telkom and have them replaced. I was also told that I had a valid concern and that they support my decision to claim two new phones. During the process of returning my faulty phones and receiving new ones the Samsung representative walked into the store and the Telkom employee that was assisting me asked her opinion on the matter. To make a long story short the representative managed to insult my intelligence, belittle me by involving other customers in the store in our conversation and also brought in my age as a contributing factor of my criticism which upset me greatly. Regardless of my age I have been a satisfied Samsung user since I can remember, I know how I like my phone set up and have a good knowledge of how to adjust settings to suit my needs and how I work with my phone. I will not say that she did not know what she was talking about or that she did not make valid points and suggestions. She did however not take into account my general knowledge of the phone. The way I was spoken to was appalling and unjustified. The way she carried on and on as if she would convince me to rethink returning the phones was upsetting but she also made the Telkom employee doubt whether he should complete the OBF process. Before she walked in and became part of this whole process I was calm and still completely satisfied with Samsung in general because I understand that sometimes things are not perfect and that is life, but the scene that this situation was made into infuriated me to the extent where I never want to see another Samsung representative ever again. Coming from a field of work where I myself deal with customers/people on a daily basis I feel like maybe a training course on how to speak to people is in order.