On similar lines, I had cause today to go to the lost property desk, which is within the left luggage office at New Street. I had found someone's clothes shopping last Thursday, on a seemingly deserted platform, but didn't have time before my train departed to do anything with it. There was no guard visible on the train I got, so I decided the best bet was to bring it back on my next visit four days later.
I didn't know where the office was, but a chap at the first set of barriers directed me to pass through his barrier, which he opened for me without question, and then through the second set, and turn right. When I got to the second set the guy manning those was absolutely adamant that I had to show a valid ticket to be let through! I explained that I had been directed to the lost property office by another staff member, but this chap wasn't having any, and in the end I had to show him my totally unrelated ticket for a journey in half an hour's time, before he would let me through. The irony was that upon leaving the lost property room I had to return through the same barriers to access platform 5. If I hadn't been travelling anyway, and had just walked in off the street, I would have effectively been barred from handing in the item that someone has lost. It's no wonder tickets rarely work when they have been put through so many barriers at that station.