I'm expecting a parcel from a supplier via Paxi

I'm expecting a parcel from a supplier via Paxi. I think the parcel is lost but they don't want to give me the details, they say they can only communicate with the sender, not me as the receiver. The problem now is that the sender can't make a call to Paxi because it's not a free call. Now I'm stuck, my small business is not working. Please advise me.