@Niamh1
Are you using the password found on a label under the router, respecting that case matters - CAPITALS must be input in capitals, and lower-case letters in lower case?
And taken care to distinguish O from 0, and capital I from lower-case l and numeric 1, and so on?
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.
