Hi Ian,
I am from SAP CAL Operations team. The reason of this failure is invalidated credentials in the CAL account.
I would like to help here but could you please first check if the instance is not running in your AWS Console? If there is no such, don't worry about any payments or leaks. Only clean up in CAL console will fix this and i will follow up to clean your Console UI.
Best Regards,
Aleksandar