Price increase upon purchase

I was trying to purchase a hard drive from the takealot website on Black Friday. I had managed to place the item in my cart but when trying to get into my cart I was moved to a page that informed me they were experiencing technical difficulties. I refreshed my browser a few times but could not get through. Finally I managed to get into my cart and proceeded to checkout. I had already filled in the delivery address and when transitioning to the next page noticed that the price had increased. I went back to my cart and was informed that the item price had increased and I had missed the offer. While I understand that placing an item in your cart can not guarantee your price, surely if you are in the process of buying (and paying for) the item the price should not suddenly increase? Very unhappy about this. I corresponded with Zandile Ndzishe but this did not resolve anything. Had I not verified the amount I would have purchased the item at the higher price. I think Takealot should review their procedures so that prices do not increase suddenly while you are busy paying for an item.