Parcel not delivered to me and was sent to previous address and not new address.

I got an sms saying my parcel has been delivered on 11/11/2019, however it was not delivered to me but they let a stranger sign for my parcel without my concern. Now its the 14/11/2019 and I still have not received my parcel and I have been calling Zando to find out what is going on but they keep on telling me that they are waiting for feedback from the couriers.