Worst online service everrrr

I placed an order and paid online on 7 December 2021. On 15 December I noticed that the order status still says processing, which for any other online store would have been delivered by then. I called their call centre and spoke to an agent who then only notified me that there was a backlog on order from Black Friday and they needed to source the item from one of their stores. What annoys me is how do you let your customers order and pay for items that you not sure is in stock or not? The agent promised me she would call me back the next day to let me know when i will be getting my order as i mentioned i wanted the order my christmas, and again for a normal online shop there would have been more than enough time get that order to me by then. The agent never called me back. I then got an email on 17 December telling then only that my order will be delayed as they still sourcing the stock. It is now 22 December and I my order still says processing online. I have never ever in my life experienced such horrible online service, even when ordering things from overseas i have received it faster than this. I normally buy from Shesha in store but the online store has really put me off, and i will not buy from them in future.