Waiting for Online Order 2 Weeks Later

I placed an order online on 14 Jul for delivery by 21 Jul. I sent an email late on 21 Jul, I was called on 23 Jul and told that the package was delivered on 18 Jul and they have to investigate where the package it. They called on 25 Jul to say they are still investigating. Today is 28 Jul I still haven't received my package or a call to say where it is or when I'm going to receive it.