ResellerRatings uses Chargebee as our payment/invoice platform. Like Stripe, Chargebee handles millions of transactions a year and you can do several things from it.
Updating payments - simply go to your account under your dashboard at the top right
Under Account > Payment
You'll have the ability to see your invoices AND update your payment information
You can check out how to login / more in management here
One Time Password
When entering into your payment portal - Chargebee will send you a ONE time password for use to gain access to your billing and card history. If you haven't recieved one when you attempt to log in with your email address, please check your junk folder. Otherwise contact us on the 'intercom' help button at the bottom right corner of the screen.