Re: There is a simple way to stop this
I applaud your intent - but it's never going to work. It relies on the mobile phone companies knowing about all the premium rate numbers both in the UK and oversees.
In the UK, the number plan (whilst not perfect) is fairly easy to understand. (01 & 02 landlines, 07 mobiles (et al), 03 & 08 non-geographic, 09 premium) Other countries number plans are less easy to understand: Brazil is one country that springs to mind for having a hiddeous dial plan.
At my work, I've had to tell our telco when a new international destination needed adding to their network routing tables. Or when they charge the wrong amount for a call 'cause they have the wrong charge band for it (mobile Vs landline, for example).
If there was a global list of these premium rate dialing codes, it *might* just stand a chance, but that would require a lot of international co-operation.