I have gone into the account update details, have updated them... and it won't save them.
This is ridiculous... No matter how many times I go in to change, and then save them, it doesn't.
As such, payment isn't going through
Account for what - streaming ot broadband?
OK - in that case, can you try it in a different browser?
Failing that, contact Now via Live Chat, and they should be able to make the change for you.
The following link, which leads you to direct contact with Now Live Chat, is for when the Community can’t help, and the Help can’t help:-
Do not be seduced by anything saying Get Help Quicker. It won’t be.