I have just moved to Pay Monthly account and have changed to a new number. I still have a few pounds left on my Pay and Go account, so have put my old Sim into a spare phone, so that I can use to credit up. When I log in to my Pay and Go number, though for a balance, there is an error message shoiwng, saying I am not a valid Prepay customer. Is this normal, and will my old phone eventually be cut off if I don't top it up?
