FAILURE TO DELIVER AS INDICATED ON PURCHASE

On Friday 4/6/21 I went online to purchase a gas heater. I found the gold air 3 panel gas heater for R999. I checked stock at rossborough branch first and no stock, so I checked Arbour Crossing branch they indicated 1 in stock so I proceeded to checkout and pay for it. I received a message shortly after purchasing it informing me of my order number *** and where to go to veiw my order status. On Saturday I went to the website and saw that delivery will take place on Monday 07/06/21. In order for me to be home when they deliver I cancelled my dental and other appointments. When I contacted customer care on Monday 07th I was informed delivery might only happen on Tues 8th as store was awaiting stock. I would like to know what happened to the 1 I saw that was in stock?