Neglegency/ Unprofessional

I have ordered at shein, after a week I received email from an email from shein and Buffalo that my delivery failed. I called Buffalo to get clarity because the is no one who called me regarding delivery. They said to me they will deliver the next day, the following day I got email that delivery was successfully . So I didn't receive my order now its 3 weeks, when I call Buffalo, they told me that they have delivered my order. The quotation is to whom did they deliver and how can they deliver without calling me first and how did they identify the person if it's me or not? I'm not happy at all. Now I lost close to 3000.