Has anybody else had this problem?

I am in London and have been trying to call the US PLat concierge. I know that there is one in London, but I was told yesterday that I need to call the US concierge since I have a US-issued card.

When I tried to call the collect number, it says the number is blocked to collect calls! Then, when I charged the call to my plat card, the Amex center immediately picks up with a recording that says "all collect calls accepted". What is up with that? Fortunately, the concierge offered to call me back, so I only had to pay (what will probably be an excessive) for the iniation charge and first few minutees on the phone.

Does this happen often, though?