Post Office Delivery Bad Service

I posted some documents, was given a tracking number. As this is my first time using it I just wanted to track it and see what’s happening. I have sent emails, with zero response, I have called, zero answer, also used the sms option where I sent my tracking number, zero response. This is my last attempt cause clearly customer service is not going to respond. I asked the guy at the post office what is the FASTEST method of delivery. These documents I sent are so important and yet I don’t know what’s happening, I should have just used Postnet again cause this is ridiculous.