Bought something online, and now no stock

I bought a fridge online on Black Friday and my order was accepted and paid for. Delivery address has been sent to the suppliers, everything. The fridge was clearly in stock at the time of me placing my order. On 29 November I was informed that the item is now suddenly out of stock and that I will either be refunded or receive discount on another item. This is completely unacceptable and boils down to bait marketing. Firstly, you as a supplier should have anticipated that on Black Friday you will have high demand for items on special, and according to the CPA you should have made provision for this high demand. What angers me more than anything is that I WAS ABLE TO BUY AND ACTUALLY PAY FOR the product online, and you had no problem accepting my money and scheduling delivery. I insist on getting this fridge at the price i paid. I just cannot understand how this item is suddenly out of stock after I have paid for it.