When I click the link to add a payment method via the link provided in the pay a bill alert I received via email, theres no button or link within that page that signals how you do this.
It turns out that this button doesnt show up when you have an adblocker enabled.
Its probably worth noting for other members that an adblocker can prevent the members centre from showing elements correctly - in this instance, the add payment method.
whatever website external linking you have embedded in your page for the payment method button needs to be reviewed, as it being caught by a browser adblock is poor website programming.
