On the back of your good experience (glad to hear of it btw), we do get instances where everything tests OK to our Indian colleagues, but there is an actual fault with the modem. I had one only on Friday, whereby I did a remote test upon receipt of the GEA fault, and everything looked hunky-dory. On site though, it became apparent that the LAN1 LED wasn't lit, therefore the modem was in synch but wasn't pushing the service through to the Hub.
That is why I questioned Walters comments. If they could interact remotely with the Hub, they would have seen it was out-of-synch, but because they can only 'see' the modem, and this
was in synch ....... the EU was given the 'charges may be applied' spiel.