Ensure that the billing address your are entering is the same address your credit card company has on file for you . Also use privacy or incognito mode.
There was a tech issue today which caused outages fr some accounts. There is a post in the announcement section . It's possible your account was one of them .
I believe that there was a tech issue today where some pols plans were renewed early causing an outage . Which is being worked on . There is a post on the announcement section and possibly you were one of the affected accounts