Takealot advertising stock they don't have

Bought a pair of mens shoes UK 12. After a week it was delivered. Box not properly sealed, box indicated UK 12. Opened it - shoes are UK 11. Did a return request. Takealot collected next day I specifically requested it to be replaced by UK size 12. 2 days later I was informed that I will be refunded no stock available. When I log on to the app the Shoe size IS AVAILABLE in UK 12... I want to order it again, but I am convinced that just like last time I will get UK11 again...