I've had an iphone simplicity (30 day rolling contract, 20 quid/month 600 mins 1200 texts with unlimited data bundle) since december.
i'm wondering: the current "unlimited data" option is "fair use" with no preset limit. can they just change this? i.e. if i get the iphone4 and continue with my simplicity plan, can they just cap my data usage or change the terms of my rolling contract?