Waiting for refund for "out of stock" items

I have ordered the 3 for R80 tomatoes ****tail juices 3 times from Woolworths online and I have NEVER had a 100% successful order. Everytime I order it's out of stock. Why can you put items in your trolley and pay for them when there isn't the stock available?!?!?! This last order was the same, I ordered 4 x the special (12 boxes), and only 9 arrived. This was in the 15/07/2025, delivery was on the 19/07/2025. I have sent 2 emails inquiring about my refund for the "out of stock" boxes and haven't received any communication back!!!! This isn't the type of service I expect from Woolworths.