I found it buried, @Cleoriff, but cannot change as I don't (tsk!) usr DD, preferring to have it either collected from a credit card (non-Refresh) or paid manually from a credit card in my O2 Card Wallet.
Maybe I need to give My O2 a kick @pgn I got to the section Manage Payment details (on PC) and it was blank....!!
Veritas Numquam Perit