Shocking service delivery

My parcel, which contains medical supplies so I don’t die, has been delivered to the wrong address. What blows my mind is someone signed for it but it’s not for them. DPD have taken two weeks and have still not found my package. Which I PAID for! The best part is that it’s a standard monthly delivery but this time who knows where it was delivered to!!! Terrible service and so disappointing that there is no urgency to help someone.