Parcel gone missing - no one can help me

On 22 January I posted a parcel for my mother from Postnet Ontdekker. This was on a Thursday, and parcel was due to be delivered on 27th. To date nobody can tell me where this parcel is. Every time I call to try and find answers, the person takes all the details but never gets back to me. I was dealing with one person, who when I called again after broken promises was informed is on two weeks leave. The next person was going to find information and get back to me within hours, but it has once again been days without answers. Is my parcel completely lost? Should I replace the stuff and resend through someone else? PLEASE don't keep me hanging any longer?????