Insulted by a staff member

I was at your store in the Fourways Mall earlier today, 5 August at roughly 2PM. I went to the bakery section to buy a pie, I was assisted by Ntombi (unsure of the correct spelling), I asked for one pie, she then asked me to take 2 as you have a sale where 2 pies cost R33, but I reiterated politely that I wanted just one. She then insulted me and said that I do not want 2 because I am fat. I felt so embarrassed and degraded. I did not fight back but when she saw that I got upset, she said that she was joking. Is this how you train your staff to treat your customers?