VERY VERY BAD STOCK CONTROL

I purchase a Girls bike on Takealot that showed stock at the CPT warehouse. All went good and my order will be delivered on the Tuesday. When I went on the Sunday on my Takealot app to track my order it shows that it was moved out to the 20th of December and there is a "!" when I click on this it status that my order was cancelled and it was returned to the warehouse. I didn't give permission to do this. Now I can not find a tube 12inch bike and Takealot do not want to take responsibility for the wrong advertising of stock that there is not.