Shein Marked My Order As Delivered But I Never Received It, Need A Solution

I placed an order on Shein on 11 July. According to the tracking information in the app, the parcel was marked as delivered on 25 July, but I never received it. When I contacted Shein through their app to report that I did not get my parcel, I was informed that they could not issue a refund. Despite the order showing as delivered, I have not received any of the items and I am left without either the products or my money. In this situation, I request a full refund for the entire order. I do not want the order to be resent and I do not wish to place any new orders with Shein.