Missing item from online package

I recently ordered some products online. On Monday the 7th August 2022, I received my package but one item was missing. The invoice included in the package showed all the items that I ordered including the missing item. I immediately phoned the call centre to tell them my table cloth I ordered was not in my package that I received. I gave my invoice number and the person promised to follow upfir me. I have heard nothing. I emailed the help centre and still nothing. I'm very disappointed. I'm forced to shop online after my recent knee replacement surgery. So this is very sad that I can't rely on your service. My box was sealed on delivery so I know it didn't disappear in transit. Please, I just want my tablecloth. That's all. Please rectify this situation.