Lost/never sent our wedding invitations

We had gone in to have our wedding invitations sent in a bulk envelope to Port Elizabeth. This is the first time we have used postnet.<br> We asked for this envelope to be sent to the postnet in moffet on main in P.E, the address and all the details were fine. The woman delelia, who seemed to us very unhelpful said its all fine and it will be sent. We asked if we need anything like a reference number or something and she said no. We had sent normal post with this envelope and those have arrived at their destinations. <br> <br> However our envelope never arrived. We went in they have absolutely no record of send it anywhere in the month of january. It is now more than 3 weeks and it has not arrived. We did not keep the receipt and when we went in this woman made it seem like its our fault and very surprised acting like she would never mess up. however speaking to her colleagues and seeing her deal with other customers makes me wonder how she is still employed. <br> <br> Now besides the cost of our postage and R300 worth of wedding invitations are lost in the ether none of the guests have gotten invitations. WE ARE FURIOUS. It is now to late to make new ones. Where have the invitations gone?