Aurora PostgreSQL cluster stuck in Upgrading status

Hi, I would like to delete an Aurora PostgreSQL cluster that is stuck in Upgrading status for several days now. I was able to use the AWS CLI to trigger the deletion of the single writer instance in the cluster and that is now in Deleting status but I am unable to delete the cluster itself. When I run the aws rds delete-db-cluster ... command, I don't get any error but it also does not delete the cluster. It remains in the Upgrading status. Any suggestions or ideas on how to proceed will be helpful. This is a dev account so we don't have technical support enabled.