Speed service couriers

I have sent a parcel with very important documents from Wellington to New York. I paid for the speed service as it was said it will take up to 7days to be delivered. However today we marked week 3 and the parcel had not been delivered yet. No one at the post office can help me with a trace code or give me feedback of previous tracking number. I will not recommend using their service to anyone as they are useless and playing with futures.