I am having the same issues have tried to buy a day pass then a week pass and even the month pass...it says my card is confirmed and then tells me wrong details when i try to pay...the robot is as much use as a chocolate teapot and no human available
Sounds like a technical issue at NowTV's end with the amount of posts in the last couple of minutes and the amount of traffic starting to mount up on the NowTV website (looking at the numbers logged in and guests).
Live Chat would be your best option.
I have the same issue, clearly the clowns at Now TV/Sky couldn't organise a **** up in a brewery. All I was trying to do was update my out of date debit card but the system they are using insists you input a house number or name in to a box that can only take 5 characters. My house name is longer than 5 and the house has no number so whatever I put in the box doesn't match the bank details for the address on the card so rejects it. Absolute garbage. Sort it out children