Ant T,
Well, I think even you have to admit you are a bit of an "edge case" then !
I don't think you can entirely blame Apple for the current configuration.
In its present state, 99.9999% of Apple users will be protected from expensive downloads because, as you yourself state, the only thing most of the world has to worry about is being charged for data over the mobile networks.
The problem with software development (at ANY manufacturer) is that its an expensive process... coding is expensive, QA is expensive, maintenance is expensive.... you therefore have to code in a style that will satisfy the majority of your users.
In ANY software development project, there will always be unforeseen "edge cases" .... when these are brought to light by the few affected users, then these are generally fixed by the manufacturer in due course.... and I hope this ends up being the case with you and Apple, although don't expect overnight results because in ANY software development workplace you have to prioritise jobs.
Believe me, I know what it's like to be an "edge case", I've found myself in one of those rare positions (because they are RARE) with other manufacturers of much more complex equipment than a simple telephone.... all it demands is patience... all manufacturers want happy customers, if its fixable without spending more man-power on it than reflects the number of users affected, then they will do so....
If, on the other hand, you feel you would be better off without Apple, then fine.... but then please don't make a song and dance of it and blame Apple for your woes given the "edge case" scenario in which you unfortunately find yourself.
I will post an "enhancement request" for you on Apple's developer systems so that at least you have another channel making Apple aware of it as well as your local store manager.