How credit notes work?
When a credit note is raised on your account, the credit automatically is assigned to the oldest outstanding invoice first.
If there is an older invoice than the invoice that has been credited, it may look in the system that you need to pay this invoice off still, but this is just due to how our credits are applied in the system.
You can always click into the relevant credit note in myservers for a full breakdown of what the credit was actually for.