I have just bought a Sony Ericsson Xperia arc phone and have a question. I'm currently on O2 simplicity which means I pay £7.50 a month for unlimited texts, then I pay £1 a day if I want to use the internet. However I have started to be charged even though I am not using the internet. I have been told to turn the data off, when not using it. Will this stop any additional charges? I'm also taking it that when I want to use the internet I just enable the data settings, then switch them off when I am done. Is this correct?