I keep trying to register my card details with Now Broadband and there's always an error not letting me save my card info. I tried calling today and it didn't work, I've tried at least a dozen times to add it via the website. It always seems to run into an error regarding my address but I'm not sure.
For extra context, we're multiple tenants and the account is under my flatmate's name but the payment card under mine. I don't think this is the cause of issue but just adding it in case.
What number did you call?
Try the number within this link. Make sure you're signed in and use the 'How to get in touch' drop down to see the number.