I had sort of a similar problem. I mailed an envelope to
the UK, paid the postage at the customer window and handed
over the envelope.
It showed up a week or two later in my post office box
(in another city). My pop picked up the mail and saw
the no-postage, so *he* took it to the customer window
at that post office and re-paid the postage. Later when
he told me what happened and teased me about forgetting
the postage, I told him that I *had* paid, they simply
didn't bother to put it on the envelope.
I dug out my receipt and next time I was in the area of
the stoopid post office, I took it in and showed it
to the guy at the counter, who turned out to be both
the man who took the postage money from me in the first
place AND was the postmaster for that branch!
After a back-and-forth, I got my money back and never
used that post office branch again.
Nyssa, who is gob-smacked that her post office box rent
is going from $98/year to $276/year and wonders why the
price of the mail clerk to put the mail in a hole in the
wall in the same building he/she is already in costs so
much more all of a sudden