Poor service delivery by Aremax

I've ordered from Shein on the the 25 Nov 2023, my shipment was cleared by aremax SA on the 4th of Dec and I was told it's on the way. I've since been waiting and the status on their system doesn't change. It's been stuck on the same spot to date. I called them over and over and am told that the shipment is still in China. Their system is devastating, I will never advise anyone to do business with them. How do I escalate this matter... please help