Online Order Delivery ?****? due to Stock Level ?

Bought a ECO 1890 water tank (on special and online + included delivery). Website showed 4 in stock before i bought. 3 post. they are rerunning special with 3 in stock. BW-Strubensvalley Roodepoort. my delivery was supposed to be yesterday 5th Sept = nothing. Now i get a call from customer care, due to stock not being available, next delivery is 16th. WHAT DA HELL??