Fragrance from truworths online canceled after 2 days of purchase

Truworths had an online sale on fragrances and I managed to purchased 1 and it allowed me to proceed with the order until the end I paid the amount requested and I even got the confirmation email that my order will be ready for collection thn yesterday I recieved an email saying my order is on the way to the store, than boom today I recieve an email saying that my order has been canceled because it is out of stock and I will get my money after 7 to 10 working day. Like Realy how is that possible? Why didn't they stop the sale after seeing that they ran out of stock. I don't want money I want what I have ordered