Missing item and still waiting

Ive received my package gro SHEIN, but there was a item missing. Ive contacted SHEIN and they advise me to contact Imile logistics. I contacted them a couple of times and send emails, without any response. In my last conversation with them they advise that tjey will investigate the issue an revert back to me, but it was only talk. Its almost 2 weeks am d im still waiting. These people are just taking money, but cant provide services. I hope SHEIN will get rid of them or orherwise they will lose a kor of customers due to this Imile Logistics.