SHEIN Order Marked Delivered But 12 Items Missing From Parcel

Yesterday I received an email stating that my SHEIN order with tracking number JJD0002279998056280 had been fully delivered. However, I only received one package containing a single item, while the other 12 items that I ordered are missing. The total value of these missing items is more than £50. I have not yet been able to resolve this and have not contacted customer service before this complaint. I kindly request that the 12 missing items from my order be identified and sent to me as soon as possible, or that the necessary steps be taken so I receive everything I paid for.