Problem with app download

I'm an old fogey (you know, the type that has just learned to switch his computer on and off unaided), and is therefore not safe to be let out with an HTC Desire Z. I'd like to download an app (to be precise, the timetables of the SBB (Swiss Railways)), but I'm told every time that "there is no phone associated with this account", even the blasted phone is sitting there, looking at the screen with me. So what should I be doing in such circumstances?

— modified on Jul 3, 2011, 6:52:00 PM