Missing item - online delivery

I placed an order online on the 26th February 2025, and fortunately was delivered the next afternoon on the 27th. This order was received by my husband, which was 4 boxes. Upon unpacking I realised we had an item missing, I raised this immediately with them, sent an email and called the customer service line on the 28th where I was told they’ll escalate it. I have called numerous times and they keep saying that they have escalated it and there is nothing they can do on their side as it states “all items were delivered”. This has been ongoing for almost a month now, numerous calls and emails sent. Not even a damn response. This is very disappointing to say the least, the level of not being bothered by all these negative comments is concerning.