False advertising

On the morning of 27 November 2017, I went online to order a book set "Diary of a Wimpy Kid". The set has been advertised as R469. I placed the order and selected COD as method of payment. When I received my confirmation email, I was surprised to see that the set now costs R549. When I queried this, I was told the following: "Hi Mpho, We're so sorry for any inconvenience caused. Kindly be advised that when an item reverts back to the normal price it means that the quantity agreed to with the supplier is sold out, therefore, it reverted back to the normal price". This is absolutely unacceptable because you cannot advertise a product for a certain price and then expect me to pay something else. The price should be changed on the website to reflect R549 and not when I checkout. As a customer, an expectation has been set that I will pay R469. You cannot then expect me to pay something else. Internal issues between the supplier and TAKEALOT have nothing to do with me. This is honestly nonsense and I refuse to accept this ridiculous explanation!!! This is like seeing a price on an item in a shop and then getting to the till and being told to pay a higher price! Really!!! Fix this!!!!!