Sorry, I didn't know the PO will not send O'nite mail to a PO Box. Give them a call anyway, and you might be able to fax them your application and work out how to get them your fee ASAP. They are good people and if you ask in a polite way, they MAY be able to help you out. Please remember that lists have to be made, classes laid out, etc, etc, etc. That is why we have deadlines.
Please remember that a request admitting that you goofed up in a quiet manner is going to get you much further than hollering or threatening.