i want my money back

I went to a shisha store on the 29/08/2019 to buy a pair of takkies I found a pair of nikes and on the boxes where the nikes was I confirmed the price with the consultant and he confirmed 1599 for the shoes as per the box. I never look at the receipt when I left the sore when I got home to fit the shoe properly and look at the receipt I was charged 1900 for the takkie. Upon my sister going back to the store to dispute the price she also found that the takkie is 1599 on all the boxes and some boxes in the same line mixed never had a price just like my box and the same consultant confirmed to her as well that the takkie is 1599 only after scanning it they discoved its actually 1900 and the manager doesn’t apologise just said it’s not their fault I was supposed to check my slip before leaving the store, I was miss leaded and over changed and based on that I don’t want the takkies I want my money back