I am wrong for a problem I have with you

Long story short. I saw an item on sale, added it to my basket added another item and paid. Takealot's system decided to change the pricing of the item on sale(I bought two of the sale item) while it was in my cart to a higher price. I paid- expecting the system to correctly add up the amounts I saw when I added the items to the cart, Apologies if my expectations were a bit too high for Takealot (also keep in mind that the payment was a few minutes after adding to the cart). Anyway, I lodged the complaint and their response was that in their terms and conditions, they are allowed to change price without letting me know. So they hid behind their terms and conditions to mislead a customer when making purchases to take more money. Basically it is like saying that its right and okay to do what they did and I should be happy with their service because they said it in their terms and conditions. So that means I'm wrong to question it? Thats good to know. Obviously, I don't agree and that is why I'm here. Is this not against the Consumer Protection Act? There must be some law that protects consumers from being taken advantage of like this. Not Happy with their attitude towards my issue.