If you encounter any technical issue or a "page not found" or "server error" you can report it at developer.blender.org.
If you have any billing, account or related query, please get in touch with firstname.lastname@example.org with as much detail on the issue as possible.
On September 14, 2019, Strong Customer Authentication (SCA) requirements went into effect in Europe. These new requirements mandate that additional authentication measures be performed for certain electronic transactions. If you are encountering renewal issues with your previously working credit card, consider removing the credit card from your payment methods and then adding it again . More info about this topic is available in a dedicated page about SCA.
If you have any question or doubt, get in touch!