To cancel your GitHub Copilot plan for your enterprise account, you need to disable GitHub Copilot for all organizations in your enterprise. See Disabling Copilot for organizations in your enterprise.
Canceling GitHub Copilot for your enterprise
Disabling GitHub Copilot for all organizations in your enterprise will cancel your enterprise's Copilot plan.
Who can use this feature?
Copilot Enterprise or Copilot Business