I am a Three customer and at the end of my contract opted to stay with them for a one year sim only tariff that suited me but has lower data (although same unlimited texts and more minutes). Upon checking my next bill online I was annoyed to see myself still on the old tariff so I phoned them to be told they had been having problems with their systems and whilst my new tariff will be honoured I am stuck in the old one for another month. They have credited me for this and given me another £20 credit on top for the inconvenience. However, if they are having problems with their systems - it may be worth checking your account. The number I spoke to them on is 0800 033 8013 - and goes thru to the Glasgow centre. I think this system problem only applies to people who have recently changed their tariff but it may be worth all Three customers checking their bills as I am unclear why it would only affect me. (Unless of course they told me porkies and the member of staff who was meant to cancel my PAC code and put me on the new tariff did not - however it seems she did but the system had a hissyfit).