Dropping calls to avoid taking ownership of lost item

I placed an order with Rentoza on 25 November and since then the tracking status shows " In-house-client scan". This morning (1 week later) I called Skynet who advised me that the parcel is still with Rentoza as they did not take possession when they were supposed to pick it up on the 25th. I then spoke to a manager at Rentoza who assured me that Skynet has taken possession of the parcel and sent me the proof of collection, signed by the driver on 25 November so it is no longer with Rentoza. This proves that the package is being kept by the courier or they lost it. So now whenever I call the Skynet call center and an agent eventually answers the phone they drop the call after I have given the waybill number. Please just deliver my item or acknowledge that you have lost it. My waybill number is UASS8CNP