Delivery confirmed however I didn't receive my package

I have been waiting for a package since December 23rd , I have been in contact with dawn wing customer care or tracking they assured that package will be delivered and I will be contacted. i checked on there tracking and it confirmed that my package has been delivered to the registered address and a person by the name of Michiel signed for it , they didn't contact me to confirm delivery and they just gave someone my package, there is no Michiel at security booth so where is my package. I have been calling to speak to a superior with no luck, no I call and my calls are dropped after waiting for 15 people in the queue. can someone take responsibility of this query.