dead end communication and parcel tracking

this is the second experience with buffalo the first experience was great second time around im having issues with them their phones don't work their whatsapp number is not monitored or maybe just being ignored their emails don't send back replies either. I have a parcel from shein that I have been waiting for and its been more than seven days since I paid for customs but can't get hold of them or track my parcel. can shein allow us to have a choice on which courier company we would like to use.