I got me Silver card activated earlier this month at the desk on departures level of terminal 3, not the office in the premium entrance area as it isn't 24/7 like the desk on the economy entrance side. The guy that helped me was overjoyed to have me at 3am saying he was getting bored of playing games on his Ipad and was glad to have someone to chat to for a bit. He then went on to try and get convince me to move to Dubai, it was an interesting conversation!