Most support tickets are one of a dozen questions wearing different words. Tell us where you are and what happened, and we will point at the page that answers it.
How do I change the card on the account?
Any admin can update it in billing settings. The change applies to the next invoice rather than the one already issued.
Four people answer these, and they wrote the pages the router points at.
Still not it?
Send us the answers you just gave and a sentence about what you expected.