I would keep checking back with them, perhaps the mailman had it for delivery when you stopped at the post office. Instead of having them turn it in to the supervisor, ask to speak to the supervisor or
call the USPS Customer Service Line, 1-800-ASK-USPS (1-800-275-8777). When you call this number during normal business hours, you will get to speak to a Customer Service Representative who will take down the details of your complaint. When you call, be sure you are prepared with all the details of your problem. Have names, dates, addresses, or any other pertinent information available, and your call will much quicker.
If you call after normal business hours, you will be connected to an automated system and will be able to leave a message concerning your problem. You will then be contacted later by a call center representative about your problem.
Hope it all works out for you! Let us know.
