AWS Support absolutely fumbled the incident, but what you should have learned from the experience, and the majority of others commenting here is: Running a business critical workload in one AWS account is a self-inflicted single point of failure. Using separate accounts for prod/dev/test (and a break-glass account) is one of #1 security best practices:

“SEC01-BP01 Separate workloads using accounts.” - https://docs.aws.amazon.com/wellarchitected/latest/security-...

Keep resources out of the payer/management accounts. Consolidated billing is fine, but the management account should stay empty.

"Best practices for the management account" - https://docs.aws.amazon.com/organizations/latest/userguide/o...

Enable cross-account backups. Copy snapshots or AWS Backup vaults to a second account so Support lockouts don’t equal data loss.

"Creating backup copies across AWS accounts" - https://docs.aws.amazon.com/aws-backup/latest/devguide/creat...

Populate Billing, Security, and Ops alternate contacts. AWS Support escalates to those addresses when the primary inbox is dead. "Update the alternate contacts for your AWS account" - https://docs.aws.amazon.com/accounts/latest/reference/manage...

Follow the multi-account white-paper for long-term org design. It is not optional reading. "Organizing Your AWS Environment Using Multiple Accounts" - https://docs.aws.amazon.com/whitepapers/latest/organizing-yo...

Maybe get some training?

https://aws.amazon.com/training/classroom/