False prices advertised

I wanted to purchase the 850g Vanilla Ensure Nutrition Shake, I checked online for the price before I went to the store and it indicated that it was R200.00. So I go to the store to purchase it and in store it says its R215.00. I told the cashier that online its a different price and they said well online sometimes has different prices. Not being in a mood to fight I paid and said I'll call customer services the next day. I call customer services the next day, all to get an explanation that each store has the right to change the prices in comparison to their competitors in their mall. So each stores price would vary based on the store located around it. What utter nonsense! How can each store just change their prices and consumers must just pay the price. Then the call center agent, "Ikraam Abrahams" , has the nerve to have an attitude and say well if its a problem then I can return it and repurchase it online. This was not an online only price, what's the point of checking prices online if in store they can change it like they want.