Johannesburg International Mail Service - Impossible to get hold of anyone

I am really at a point where I do not know what to do next. I bought items from the USA which was send through the United States Postal SErvices. It arrived in SOuth Africa and was scanned in at the Johannesburg International Mail Service on the 19th of March. THis number is listed as your contact - ***0. It is not even ringing. Then you have this number - ***, it goes through to the automated response which is always the same - we are experiencing high call volumes and you must hold on. I have stayed on line for 50 minutes without getting to talk to anyone. I have also send a few e-mails without getting any reply. I would love to know where my parcel is.