Cell C tell me I'm a lier

During the past week I did a sim swop on my data card and bought a new SIM Card to let my son use it as he is going on holiday with friends. I went to Carnival Mall Cell C and was help by Desmond. When he did the sim swop he gave me the card and told me this is the data card which I put in the envelope I had with me, because my device was at home. Then he did the normal phone SIM and gave it to me telling this is my data sim. I told him that he just gave me a data sim, then he fiddled on the computor telling me this is the phone sim. As I went off I gave my son the Cell C sim and see him off with his friends. I got home and waited 3 hours but the data sim did not project any data. Yesterday on 26-7-2018 I went back and Desmond helped me again. He checked and told me that the nr I gave my son is the data sim. The one he told me, in front of a line supervisor who passed his computor at that stage, was the cell sim. All would have been fine at this point but he turned around, telling me he did it correct and I was confused. Now the point is, I am not only highly educated but also a qualified English Teacher and he is not only rude, but a disgrace to your Company by making your cutomers liers to their face. This is totally unacceptable and would've been great if you could really get Desmond NOT to work with public as he is cheecky and remind me of a militant radical. The quality training I've picked up the last 3 times I was at your Cell C Carnival Mall is chaotic.