The Virtual Machine Instances created on Onidel Cloud Platform have Automatic Renewal turned on by default. This prevents the service from being suspended in case you don't manually pay the invoice before due date. Automatic Renewal only applies to invoice based billing periods (monthly and longer). There is a similar concept for Hourly Billing called Auto Recharge. The invoice amount will be deduced from credits available in the account or subscription based payment methods.
You can verify it being enabled by navigating to Compute > Virtual Machine > (select your VM) > Billing. The Auto Renewal field will say ENABLED.
The Auto Renewal takes place 1 day (24 hours) before the due date. You need to cancel the service manually before that time if you do not wish to be billed for the next period.
If you already had been billed but did not want to renew the service, please contact our customer support as soon as possible to get the account credits returned and service cancelled.