

Did you ever adjust your budgets in your settings for your account: https://github.com/settings/billing/budgets
I also have the free account, and I never touched the budgets section. In here, GitHub action budget is set to $0 and has Stop usage enabled.
If these settings are set to $0 and you got charged, then I guess you can open up a case support case, since that seems like a bug.
Awesome glad that worked out