Companies can charge you whatever the hell they like, provided they give you a heads up and an option to cancel like they have (some contracts I think say have to give you 30 days notice but that depends on the company) Its not very customer friendly but I don't think there is anything stopping them unfortunantly. Edit - As chris said, its very cheeky pulling the whole "Systems cant cope" cop-out, its not the customers fault its their's. But on the other hand is anyone really going to make a fuss about a potential 32p saving