Poor service

On the 7th of July I made an online purchase and the expected time of delivery was the 20th to 25th July. Everytime when I tracked my order the delivery dates are moved to later dates. I tried sending them a message on Twitter and they did not respond. I then tried the chat box and the agent told me that some of the items is out of stock, I asked how coz when I made the purchase they were in stock? She couldn’t answer and said I should wait for the delivery date but every time the delivery date is moved to a later date. It’s been close to a month now and I’m still waiting for my order. The order status has always been “being prepared” since since. This is very frustrating and such an inconvenience