Complaint bad service

I ordered stuff from Zara 2and half weeks and was meant to be delivered by Aramex to my surprise I get an SMS that my stuff has been delivered and signed for while I don’t remember any of that nor ever received my items.

When I tried to call them No response I had to Dm on Instagram and all they could say was we will look into it and I’ve not got my stuff.

How do you deliver something without calling the person without confirming

I need an answer!!!!