I got. I got some orders mess up in China warehouse somemore. order 5 items, 2 left out in China warehouse.

talking to the forwarding support. (yes very hard to communicate even thou I can speak/type in Mandarin)
tell them to re-ship the missing parcel OR re-locate where is the parcels in their warehouse

Also, you need to communicate to the seller to verify the parcel, see whether have been signed/delivered to your forwarding warehouse or not.

I have 1 parcel left in the warehouse that they left out to send, now they try to resend to me again. Another 2nd parcel was delivered&signed by forwarding warehouse but, they couldn't locate it due to seller (this is seller fault) didn't include the tracking number provide to the forwarding warehouse. So forwarding have no idea that parcels is for who. But the 2nd parcel also resolved as I manage to get the tracking number from seller and provide to forwarding customers support, and she help me to update my system info and try to re-ship to me.

Yes, no tracking will be provided. So just fingercrossing. That is all you can do. I'm same situation as yours.