Terrible service from Buffalo couriers

I have a parcel that was supposed to be delivered on the 17th of December and it delayed .I called them to change addresses because I wasn’t going be home by the time they delivered the late parcel .To this day I still have received it instead was told in the Shein website they had returned it to the warehouse because they can’t find the address ,bare in mind they did not even once call to confirm the address or even attempt to deliver my parcel to the address I gave them...I am absolutely disgusted by their service ,the worse you can’t even reach them on the phone ,they don’t even reply when sent emails.The parcel has my child’s Christmas clothes so it’s a matter of urgency and don’t know how to get help.