i dont like o2 after all of my bills i had
as soon as they send you the email for your monthly bill and send the letter the next load of minutes and texts come through.
Took me quite a while to figure out how to reasd and understand the online bill thing, you just check it as you go along, but it tells you how much you have gone over and how much you have to pay and how much you owe from previous months etc etc