false marketing

Saturday the 10th of July, Edgar's had 50% off on selected items that I purchased, all items did not scan automatically, the cashier who was assisting me had to call the manager to authorize but to my surprise when I got home my underwear had the red dot sticker and I didn't get the 50% . I took them back to the store with the original tags still attached but the store manager was not helpful at all as her first words were \we did not have 50% off on underwear"I then asked about the red dot on the price tag and that's when she asked someone and they confirmed that the underwear was on special so she said \""give the customer discount\"" I advised her I did not want cash back but wanted to take underwear as it was \""buy one get one free\"" but she refused! She gave me back the R90. I am not happy at all as this is false marketing and I want to get another pair of undies free!"""