@Anonymous User
It would help for us to know what the error messages says, exactly.
What is your Visa Card, exactly? If it is Visa Debit with a large UK bank it should be OK, but if it is prepay, not sterling, or with a challenger bank, there may be an issue.
So can you check what sort of Visa card it is, and who with, and let us know?
Set a Payment PIN on your account so that no-one but you can buy memberships on it.
Check your bank accounts monthly for any other unexpected payments to Now.
That way you can at least nip them in the bud, while you and Now figure out whose fault they are.
