Bad service from The Courier IT

We are disappointed with the service we are getting from The Courier IT, we shipped a shipment on waybill *** on the 03rd April 2024 on over night services, till todate the customer has not received the parcel. We have asked on numerous occasions for the Courier IT team to phone the customer and explain why the parcel has not been received but no one is taking responsibility for this. We got the cell number of the branch were the parcel is situated but he is not taking our call. Can some one from The Courier IT kindly explain this very bad service and also contact the customer.