Hi. I have recently changed from contract to pay and go go go on the £10 a month option that gives me 250mb a month. Just two weeks in and I had 20mb remaining, but got a message about an extra 50mb usage that has been added and they have charged me a £1 for the privilege. My iphone data counter says 229mb used too. A person tried to explain it to me last night from customer service online, but I didn't understand why I am being charged if I have not gone over my limit. Can somebody explain this or had a similar situation? Many thanks. Ben