Advertised price honored - Mark out of stock when prices change

Just received the worst from Xpress Trading via Takealot. I've placed an order on the 20th December 2021 and waited so long for the order. Delivery should arrive the 12th January so I wait. Now the canceled part of the order saying there is no stock but when I click on the stock it shows available and I can order the same stock again but now the price is double. I paid and waited for the stock now the price has changed and they mark it as not available.